Ubuntu - Overview of TCP/IP

TCP/IP is a suite of communications protocols that define how different types of computers talk to one another. It’s named for its foundational protocols, the Transmission Control Protocol and the Internet Protocol. The Internet Protocol provides logical addressing as data moves between hosts: it splits data into packets, which are then forwarded to machines via the network. The Transmission Control Protocol ensures that the packets in a message are reassembled in the correct order at their final destination and that any missing datagrams are re-sent until they are correctly received. Other protocols provided as part of TCP/IP include:

Address Resolution Protocol (ARP)
Translates between Internet and local hardware addresses (Ethernet, etc.).

Internet Control Message Protocol (ICMP)
Error-message and control protocol.

Point-to-Point Protocol (PPP)
Enables TCP/IP (and other protocols) to be carried across both synchronous
and asynchronous point-to-point serial links.

Reverse Address Resolution Protocol (RARP)
Translates between local hardware and Internet addresses (opposite of ARP).

Simple Mail Transport Protocol (SMTP)
Used by sendmail to send mail via TCP/IP.

Simple Network Management Protocol (SNMP)
Performs distributed network management functions via TCP/IP.

User Datagram Protocol (UDP)
Transfers data without first making a persistent connection between two
systems the way TCP does. Sometimes called unreliable transport.

TCP/IP is covered in depth in the three-volume set Internetworking with TCP/IP
(Prentice Hall). The commands in this chapter and the next are described in more
detail in TCP/IP Network Administration and Linux Network Administrator’s
Guide, both published by O’Reilly.

In the architecture of TCP/IP protocols, data is passed down the stack (toward the
Network Access Layer) when it is sent to the network, and up the stack when it is received from the network.

Source of Information : OReilly Linux in a Nutshell 6th Edition

Ubuntu - Overview of Networking

Networks connect computers so that the different systems can share information. For users and system administrators, Unix systems have traditionally provided a set of simple but valuable network services that let you check whether systems are running, refer to files residing on remote systems, communicate via electronic mail, and so on.

For most commands to work over a network, one system must be continuously running a server process in the background, silently waiting to handle the user’s request. This kind of process is called a daemon. Common examples, on which you rely for the most basic functions of your Linux system, are named (which translates between numeric IP addresses and more human-readable alphanumeric names), cupsd (which sends documents to a printer, possibly over a network). Most Unix networking commands are based on Internet protocols, standardized ways of communicating across a network on hierarchical layers. The protocols range from addressing and packet routing at a relatively low layer to finding users and executing user commands at a higher layer.

The basic user commands that most systems support over Internet protocols are generally called TCP/IP commands, named after the two most common protocols. You can use all of these commands to communicate with other Unix systems in addition to Linux systems. Many can also be used to communicate with non- Unix systems, almost all systems support TCP/IP.

This section also covers NFS and NIS—which allow for transparent file and information sharing across networks—and sendmail.



TCP/IP Administration
arp Manipulate address resolution protocol tables.
dig Query domain nameservers.
ftpd Server for file transfers.
host Print host and zone information.
ip Network configuration tool with Cisco IOS-like syntax. Replaces ifconfig, route, and
arp on some systems.
ifconfig Configure network interface parameters.
named Translate between domain names and IP addresses.
netstat Print network status.
ping Check that a remote host is online and responding.
pppd Create PPP serial connection.
quagga Routing daemon.
rdate Notify time server that date has changed.
route Manage routing tables.
routed Dynamically keep routing tables up to date.
slattach Attach serial lines as network interfaces.
sshd Server for secure shell connections.
tcpdump Write network packet information to screen or file.
telnetd Server for Telnet sessions from remote hosts.
tftpd Server for restricted set of file transfers.
zebra Routing daemon.



NFS and NIS Administration
domainname Set or display name of current NIS domain.
makedbm Rebuild NIS databases.
rpcbind DARPA port to RPC program number mapper.
portmap The old name for rpcbind.
rpcinfo Report RPC information.
ypbind Connect to NIS server.
ypcat Print values in NIS database.
ypinit Build new NIS databases.
ypmatch Print value of one or more NIS keys.
yppasswd Change user password in NIS database.
yppasswdd Update NIS database in response to yppasswd.
yppoll Determine version of NIS map at NIS server.
yppush Propagate NIS map.
ypserv NIS server daemon.
ypset Point ypbind at a specific server.
yptest Check NIS configuration.
ypwhich Display name of NIS server or map master.
ypxfr Transfer NIS database from server to local host.


Source of Information : OReilly Linux in a Nutshell 6th Edition

How to Avoid Sneaky Fees

SICK OF BEING nickel-anddimed? Here’s how to fight some of the most egregious stealthy charges. For additional tips on fighting sneaky fees, go to find.pcworld.com/63899.

1. Sneaky Fee: Your wireless carrier charges you for storing contacts remotely or subscribing to ringtones, even though you didn’t request the services.
FEE FIX: Fight the charges with your carrier. If that doesn’t work, contact the Better Business Bureau for help. Look for alternatives, too: Yahoo Mobile offers a free mobile address book.

2. Sneaky Fee: You have your ticket, but when you get to the airport, the airline says you owe an extra $125 for transporting your bags.
FEE FIX: Most airlines charge $25 for checking a second bag, and they heap on heftier fees (up to $100) for overweight bags. American Airlines charges $15 for the first bag. To avoid the charges, pack light. You can also shop around—Orbitz offers a handy chart (find.pcworld.com/63900) that breaks down how much extra you will pay for bags, meals, and snacks with different airlines.

3. Sneaky Fee: Your cable company’s triple-play (TV, Internet, and phone) package charges you extra for a 20-mbps Internet connection, but you’re getting only 5 mbps. You also pay extra for premium phone features such as call forwarding, but you’ve never used them.
FEE FIX: Run an Internet speed test at a site like Broadband- Reports.com; if the speed is slower than expected, ask your provider for a discount. Investigate your service provider’s other packages with fewer bells and whistles, and request a no-penalty transfer. Threaten to take your business elsewhere if your provider doesn’t agree.

4. Sneaky Fee: Wachovia Bank charges $5.95 a month to download data to Microsoft Money, QuickBooks, or Quicken.
FEE FIX: A number of banks charge similar fees. Ask if you can switch to an account that doesn’t charge to download data; at Wachovia, the fee is waived if you have a “premium” savings account that maintains a $5000 balance.

Source of Information : PC World December 2009

Ubuntu Disk Usage Analyzer

Disk space usage is one of the hardest things to manage on an Ubuntu system. With applications getting larger and digital multimedia becoming more popular, there never seems to be enough disk space available to do everything you want.

The problem with running out of disk space is that often you don’t have a clue as to what caused the problem. With just the Nautilus file-browsing tool, you can’t easily tell where all of the disk space is being used. Fortunately, Ubuntu provides a graphical tool to help you determine where all your disk space is going.

The Disk Usage Analyzer tool provides a quick and easy way to examine the layout of your Ubuntu filesystem and identify areas where disk usage is great. To start the Disk Usage Analyzer tool, click Applications -> Accessories -> Disk Usage Analyzer. The main window.

The main window displays the current state of the Ubuntu filesystem. The window displays the filesystem summary information at the top (the total amount of disk space in the complete filesystem, the amount used, and the amount available). If the filesystem contains multiple partitions, this window summarizes the totals of all of the partitions used in the filesystem.

The left side of the main window displays a graphical bar indicating the percentage of the filesystem disk space used, along with the numeric total. The right side of the main window displays a treemap of the results. A treemap graphically displays the hierarchy of each folder in the system. The default treemap shows the filesystem as a whole.

To perform a detailed analysis of your system, select one of the four scanning buttons in
the toolbar:
• Scan Home: to analyze the folders contained in your home folder
• Scan Filesystem: to analyze the entire filesystem
• Scan Folder: to single out a folder to analyze
• Scan Remote Folder: to scan a remote filesystem

Be careful when selecting to scan the entire filesystem or a remote filesystem. Analyzing the disk space requires reading the entire disk area. This process can take some time, depending on the size of the disk and, in the case of a remote scan, network connectivity speeds.

The treemap view can seem confusing at first, but once you get the hang of it you’ll see that you can glean quite a bit of information from the treemap.

The treemap works from the core of the diagram outward. The core represents the top level of the tree. In my example, because I performed a home scan, the core is my home folder, /home/rich. If you hover the mouse pointer over the core, it shows the name of the folder and the amount of disk space used by that folder.

The next layer of rings depicts the next level of folders. In my home folder I have three subfolders. Each subfolder is a section of the first-layer ring, and its size is relative to the amount of used disk space in that subfolder.

The second layer of rings relate to the first layer. If there are subfolders beneath a subfolder, they appear in the second layer of rings, above their parent folder. Again, each folder in the second layer has a size relative to the amount of disk space it uses.

This process continues for however many subfolders are contained in the filesystem being analyzed. You can quickly spot areas that use the most disk space by looking at the relative size of the ring sections (you can compare ring section sizes only on the same layer). This tool provides a great way to see at a glance where all of your disk space is going!

Source of Information : Wiley Ubuntu Linux Secrets

Ubuntu Log Files

An important part of Ubuntu system administration is knowing what’s happening on the
system. Because there’s so much activity happening behind the scenes, it’s often hard
to keep tabs on your workstation. Fortunately, Ubuntu provides a relatively easy way for
you to look at what’s happening on the system. This section walks through the use of log
files and explains how to easily view them all from one location.


Ubuntu Log Files
Ubuntu provides several levels of log files for the system. Log files are used by processes
to track errors, warnings, and general items of information that may be important. It’s
usually a good idea to take a peek at the log files on a regular basis to see what’s happening
on the system.

The process that controls logging on the Ubuntu system is syslogd. The syslogd process
runs in the background and directs log messages from applications and the Linux kernel
to different log files. Because there’s so much activity going on, Ubuntu uses several
different log files to track different features of the system. All of the log files are stored
in the /var/log directory on the Ubuntu system.



The Ubuntu Log Files
auth.log System authentication events, such as login attempts

daemon.log Background process events

kern.log Linux kernel events

messages Standard system and application events

syslog System errors

user.log User events

Xorg.0.log X Window system events


Fortunately, you don’t have to hunt for each of these log files individually. Ubuntu provides a handy utility that helps manage all of the log files from a single graphical interface.


The System Log Viewer
The System Log Viewer is a utility in the Administration menu (select System ->
Administration -> System Log from the Panel menu). It allows you to quickly view all of the configured log files from a single location. The System Log Viewer window has three sections:

• The log file list: Lists the log files available to view. Log files with data that have been added since the System Log Viewer was started appear in bold.

• The calendar: Allows you to select a day from the log files to view. Ubuntu creates a new version of each log file each day. You can view any of the available daily log files by selecting the date in the calendar. Days with available log files appear in bold.

• The log viewer: Displays the contents of the selected log file.

The System Log Viewer uses monitored mode to watch the log files in real-time. This mode notifies you of new log file entries by displaying the log filename in bold in the log file list and making the new entries appear in bold in the log viewer. If your system is experiencing a problem that is quickly filling up the log file, you can disable monitored mode by selecting View -> Monitor from the menu bar.


The log files used by the syslogd process are defined in the /etc/syslog.conf file. This file defines what type of log entries are stored in which log files.

Log entries are classified by a tiered system, from lowest to highest priority:
• debug: application debugging messages
• info: informational messages
• notice: event notices from applications
• warning: minor error messages
• err: an error condition in an application
• crit: a critical system error
• alert: a system error that requires immediate action
• emerg: an error that prevents the system from running

Some Linux distributions provide a single log file for handling critical and alert messages, but Ubuntu doesn’t use this technique. Instead, it separates log messages by source and importance.

For example, you’ll find four log files for logging mail activity on the Ubuntu system: mail.error, mail.info, mail.log, and mail.warn. Each log file contains messages for the specified log level for the mail system.

Source of Information : Wiley Ubuntu Linux Secrets

System Monitor tabs – Resources

Clicking the Resources tab provides a quick graphical overview of the hardware status of the system:


There are three graphs displayed:
• CPU History: Displays the running real-time CPU percentage utilization. If the system contains more than one processor, each processor is shown as a separate history line.

• Memory and Swap History: Displays two running real-time graphs, one for the amount of memory used by the user and one for the amount of swap space used by the user.

• Network History: Displays the amount of data sent and received from the network interfaces.

Each graph displays the values for the last minute of operation, starting with the current time on the right side of the graph. The Resources tab can give you a quick overall picture of how your system is doing. If you see that the CPU or memory usage is running high, you can flip over to the Processes tab and sort the list based on that parameter.

Besides the graphical view, the Resources tab displays the current real-time information for each value, under the graph. The CPU History displays the current CPU load as a percentage of the CPU capacity. The Memory and Swap History displays the physical and swap memory areas used, as a pie chart icon. The more memory or swap space used, the more of the icon is filled. The Network History displays both the sent and received data on the network interfaces. It displays graphs of the current KB/s data flow on the network interfaces, as well as a numerical value of the total data sent and received since the system was started.

Source of Information : Wiley Ubuntu Linux Secrets

System Monitor tabs – Processes

In the Linux world, processes are the programs running on the system. It often helps to know what processes are running on the Ubuntu system, especially because many of them run in background mode. Processes running in background mode don’t appear on your desktop, so you have no way of knowing they’re running. These programs perform most of the behind-the-scenes work, such as monitoring the battery level in your laptop and scheduling programs to run at specific times.

Processes appear in a table format in the window display. The default view shows all processes currently being run by your user account. Alternatively, you can watch all of the processes running on the system, or just the ones that are actively working, by clicking the View menu item from the menu bar and selecting which option you want to view.

Selecting the Dependencies entry in the View menu reorders the process list to show which processes started which other processes. This option produces a drop-down tree, with parent processes at the top level and, below that, any child processes that the parent started. You can roll up the children processes and display only the parent processes by clicking the arrow icon next to the parent process.

You can sort the process rows in the list based on any of the table columns. For example, to see what processes are using the largest percentage of CPU time, click the % CPU column heading. The System Monitor automatically sorts the rows based on percentage of CPU usage. Clicking the column heading a second time reverses the order of the list.

You can customize the table by adding or removing data columns for the processes. Click Edit -> Preferences with the Processes tab selected to see the options available for the
Processes tab.


System Monitor Process Table Columns
Process Name: The program name of the running process

User: The owner of the process

Status: The status (either sleeping or running) of the process

Virtual Memory: The amount of virtual system memory allocated for the process

Resident Memory: The amount of physical memory allocated for the process

Writable Memory: The amount of memory allocated to the process currently loaded into physical memory (active)

Shared Memory: The amount of memory shared between this process and other processes

X-Server Memory: The amount of memory the process shares with the X Windows (GUI) server

% CPU: The percentage of total CPU time the process is using

CPU Time: The actual CPU time the process is using

Started: The time the process started running

Nice: The system priority of the process (higher nice numbers have lower priority
on the system)

ID: The unique process ID (PID) the system assigned to the process

Security Context: The security classification assigned by the SELinux security system

Command Line: The name of the command and any command-line arguments used to start it

Memory: The amount of system memory the process is using



There are also a few other options you can set while you’re in the Properties dialog box of the Processes tab:

• Update Interval in Seconds: Specifies how frequently the System Monitor
refreshes the process table data.

• Enable Smooth Refresh: Gathers new process information before refreshing the process table data, rather than refreshing table data as it gathers process information.

• Alert Before Ending or Killing Processes: Produces a warning that you are about to terminate a running process.

• Solaris Mode: Calculates the percentage of CPU utilization based on the number of active CPU cores. Thus, if two separate processes are maxing out two separate CPU cores, they would both show 50 percent CPU utilization instead of both showing 100 percent.

You can also control processes that you own from the Processes tab. Right-clicking a process produces a menu that allows you to stop, end, or kill a process, along with entries that allow you to change the priority of the process.

The System Monitor allows you to stop only the processes that you own. These are processes that your desktop started when you logged in and any programs or applets that you run from your desktop environment. Unfortunately, it doesn’t tell you that. It’ll allow you to select a process that you don’t own and click the End Process button. However, the attempt to end a process you don’t own will fail.

Source of Information : Wiley Ubuntu Linux Secrets

Ubuntu System Monitor tabs – System

The System tab provides an easy, one-stop-shopping location to find basic information
about the system. There are three sections in the System tab:

• Ubuntu: Provides information on the version of Ubuntu installed, the Linux kernel version, and the GNOME desktop version.

• Hardware: Displays the processor type and the amount of physical memory installed in the system.

• System Status: Displays the amount of disk space available on the system.
Although not a major source of information, the System tab does provide some of the basic things you might be curious to know about your Ubuntu system, or might need to know if you stumble across another Ubuntu system and need to know what it’s running.

Source of Information : Wiley Ubuntu Linux Secrets

Ubuntu - Using the Command Line

Although it can be done, it’s usually not a good idea to directly edit the /etc/passwd or
/etc/group files. Bad things can happen, and you wouldn’t want them to happen while you’re in the middle of editing one of those two files! Instead, the safer way to manage user and group accounts from the command line is to use the two commands explained in this section.


The User Commands
When working on the command line, you should use the adduser command to create a new user or add a user to an existing group. To add a user with the adduser command, use this format:
sudo adduser --home /home/rich rich

This command creates the new user account, rich, and creates a home folder at /home/ rich for the account.

You can also use the adduser command to add an existing user account to a group:
sudo adduser rich users

This command adds the username rich to the users group.
The deluser command deletes a user account from the system:
sudo deluser rich

By default, the deluser command doesn’t remove the home folder of the user. To do that, you need to add the --remove-home parameter:
sudo deluser --remove-home rich

Similar to the adduser command, you can use the deluser command to remove a username from a group:
sudo deluser rich users

These two commands give you complete control over user accounts from the command line, but there are more commands for controlling groups, discussed next.


The Group Commands
As you might have guessed by now, you can use the addgroup command to add a new group to the Ubuntu system:
sudo addgroup sales

This command creates the new group, sales, and automatically assigns the next available group ID value to it. To add users to the group, use the adduser command, shown in the previous section.
Finally, to remove a group, there’s the delgroup command:
sudo delgroup sales

This command removes the group from the system, but any files or folders that you assign group privileges to will retain the group ID value.


If a group is set as the primary group for an existing user account, Ubuntu will prevent you from deleting it. If you want to ensure that you delete empty groups only, you can add the --only-if-empty parameter to the delgroup command. If any users belong to the group, Ubuntu will prevent you from deleting the group.

Source of Information : Wiley Ubuntu Linux Secrets

User and Group Files

Ordinarily, it’s a good idea to let the Ubuntu graphical utilities do all the hard work on the workstation, but user and group management is one of those areas where it helps to know what’s happening under the hood. You may run into situations where you have only the command line available, and it helps to know how to manually add or modify a user account or group.




The Users File
Ubuntu uses a system called shadow passwords to keep the encrypted passwords for each user in a secure location. This system requires using two separate files to track user account information.

The /etc/passwd File
The primary user account file is the /etc/passwd file. Despite what it says, that’s not where user account passwords are stored. This file is set to be readable by every account on the system, because applications often need to know the users on the system.
A sample entry in the /etc/passwd file is
rblum:x:506:506:Rich Blum:/home/rich:/bin/bash

The entry contains seven data fields, each separated by a colon:
• The username
• A placeholder for the password
• The user ID number
• The group ID number
• The full name of user
• The home folder of the user
• The default shell

In the original days of Linux, the /etc/passwd file contained the actual encrypted version of the user’s password. However, the /etc/passwd file must be readable to all users on the system so that the system can validate them. This requirement left the user passwords vulnerable to brute-force attacks using password-cracking software.

The solution to the problem was to hide the actual passwords in a separate file that’s not readable by any user.

The /etc/shadow File
The /etc/shadow file is a secure file where Ubuntu stores the actual user account password, along with some other information about the account. Just like the /etc/passwd file, the /etc/shadow file contains a separate line for each user account.

A sample line from the /etc/shadow file looks like this:
rblum:Ep6sgekrHLChF.:10063:0:99999:7:::

The shadow password file contains eight data fields, each separated by a colon:
• The username
• The encrypted password
• The number of days since the password was last changed
• The number of days before the password may be changed
• The number of days after which the password must be changed
• The number of days to warn the user of an upcoming password change
• The number of days since January 1, 1970, that the account has been disabled
• Reserved data field that’s not used




The Groups File
Ubuntu keeps track of all the group information in the /etc/group file. This file has each group on a separate line, using the format:
admin:x:115:rich

The group file contains four data fields, each separated by a colon:
• The group name
• A password, if assigned to the group
• The group ID value
• A comma-separated list of user accounts that belong to the group


Source of Information : Wiley Ubuntu Linux Secrets

Ubuntu Groups

Individual user accounts are great for keeping documents and folders private on the Ubuntu workstation, but they are not at all useful for sharing documents and folders. Sharing documents is a common practice in many work environments.

The Ubuntu system provides another privilege level that facilitates sharing documents and folders. Groups are a collection of user accounts that have a privilege requirement in common. For example, you can create a group called “sales” that has read and write privileges to a folder specifically used for the sales team. Any user account that’s a member of the sales group will have full access to any document in that folder.

Individual users can be members of more than one group, although only one group is considered the main group for the user account. The main group is what Ubuntu uses to assign group privileges on any files or folders a particular user creates. By default, Ubuntu creates a separate group for each user account to use as the main group. To keep things simple, Ubuntu names the user’s group the same as the user account username.

The Ubuntu workstation comes with lots of groups already configured in the system. If you look at the groups, some of them should look similar to the options available in the User Privileges tab when you add a new user.

Ubuntu creates special groups to control access to features on the system, such as administering the system and using specific hardware devices. To allow a user access to these features, Ubuntu assigns the user account to the appropriate group. Besides these groups, Ubuntu also creates groups to be used by specific applications and services running on the system.

All of the special groups have group ID values lower than 1,000, allowing Ubuntu to easily separate the special groups from the user groups. You can manage any of the groups on the system, but it’s a good idea not to mess with the special groups unless you know what you’re doing. Otherwise, the related services may break!


The Default Ubuntu Groups
root Assigned to the root administrator account

users Used in some Linux distributions to contain all of the users on the system, but
not used in Ubuntu

libuuid Allows members to use external filesystems

syslog Allows members to access the system logs

klog Allows members to access the kernel log

scanner Allows members to access an attached scanning device

nvram Allows members to add modules to the kernel

fuse Allows members to use the FUSE filesystem to mount removable media in their
home folder without administrative privileges

ssl-cert Special group used to control encryption certificates used for the server

lpadmin Allows members to administer printers on the system

crontab Allows members to schedule jobs for execution

mlocate Allows members to use the mlocate database to locate files and folders on the
system

ssh Allows members to use an encrypted connection to communicate with a remote
device

avahi-autopid Special group used to control the automated IP detection software, which can
determine an IP address on a network

gdm Special group used for controlling the GNOME desktop services

admin Allows members to control administrative functions on the system, such as adding
programs and new user accounts

pulse Allows members to use the audio configuration utilities

pulse-access Special group used to control the audio detection services

pulse-rt Special group used to control the audio real-time service features

saned Special group used to run the software that controls network access to your local
scanners

messagebus Special group used to control internal application communications on the system

avahi Allows members to use the automatic network device detection feature to detect
devices on the network

netdev Special group used by internal communications services

polkituser Special group used by Ubuntu policy services

haldaemon Special group used by the Linux hardware detection services

Source of Information : Wiley Ubuntu Linux Secrets

Ubuntu - The Screen Resolution Utility

The X.Org environment in Ubuntu is rapidly developing and changing. Further advances and ideas are implemented in each new Ubuntu distribution. Currently, the core utility for configuring your video settings in the Ubuntu desktop is the Screen Resolution utility.

Start the Screen Resolution utility from the Panel menu by selecting System -> Preferences -> Screen Resolution. The main Screen Resolution utility dialog box.
The Screen Resolution dialog box is pretty basic. There are only a few things you can modify here:
• Resolution: Select the screen resolution from a list of supported resolutions for your video card and monitor combination. X.Org automatically detects resolutions that are supported and displays only those resolutions.

• Refresh Rate: Select the screen refresh rate for your monitor.

• Rotation: Set the screen orientation for the monitor. The options are
- Normal: Display the desktop at the normal orientation for the monitor.
- Left: Display the desktop using the left side of the monitor as the top of the desktop.
- Right: Display the desktop using the right side of the monitor as the top of the desktop.
- Upside Down: Display the desktop using the bottom of the monitor as the top of the desktop.

• Mirror Screens: Create identical desktops on dual monitor setups instead of expanding the desktop to both monitors.

• Detect Displays: Re-scan the video cards and monitors for the workstation.

The Mirror Screens option determines how X.Org handles two or more monitors connected to the workstation. When you select the Mirror Screens check box, X.Org duplicates the desktop on both monitors. However, when you deselect the check box, X.Org separates the two monitors and distributes the desktop layout between them.

When you use this feature, more screen areas appear on the Screen Resolution window area, one box for each monitor connected to the workstation. You can drag and drop the different monitors in the window. The location of the monitor determines which part of the expanded desktop it displays. If you set the monitor images side by side, the desktop will expand sideways between the monitors. If you set the monitor images one on top of the other, the desktop will expand vertically between the monitors. Each monitor image has its own group of settings. Click on a monitor image to view the settings for that monitor. By default, X.Org will set the display resolution of the two monitors to their highest common value. If you plug a second monitor into a laptop to use as a cloned monitor, make sure that the additional video port on the laptop is enabled in the system BIOS settings. Some laptops disable external video ports when not being used.

Source of Information : Wiley Ubuntu Linux Secrets

Linux X Windows Software

Over the years, two X Windows software packages have emerged in the Linux world:
• XFree86
• X.Org

Let’s take a quick look at both of these packages.

XFree86
For a long time, the XFree86 software package was the only X Windows package available for Linux. As its name implies, it’s a free, open-source version of the X Windows software intended for the x86 computer platform.

Unfortunately, XFree86 is notorious for being extremely hard to configure and get working properly. It uses a cryptic configuration file to define the input and output device settings on the system, which is often confusing to follow. Having the wrong values set for a device could render your workstation useless! However, because XFree86 was once the only way to produce graphical windows on Linux PCs, it was necessary to learn how to use it. As time progressed, several attempts to automate the XFree86 configuration were made. Many Linux distributions used a user-interactive method of automatically generating the XFree86 configuration file. Several dialog boxes would appear during installation, prompting the installer to select the video card and monitor setup from a list. The responses were then used to generate a configuration file.

There were also attempts at trying to automatically detect video card, monitor, keyboard, and mouse settings. Some of these attempts were better than others. These efforts, though, did eventually lead to another X Windows software package.


X.Org
More recently, a package called X.Org has come onto the Linux scene. It too provides an open-source software implementation of the X Windows system, but in a much more user-friendly way. It uses a combination of scripts and utilities to attempt to automatically detect the core input and output devices on a workstation, then creates the configuration file based on its findings.

X.Org is becoming increasingly popular, and many Linux distributions are starting to use it instead of the older XFree86 system. Ubuntu uses the X.Org package to produce the graphical X Windows you see for your desktop.

When you install Ubuntu, it goes through a series of steps to detect the input and output devices on your workstation. During the installation you may notice a time when it scans your video card and monitor for supported video modes. Sometimes this causes your monitor to go blank for a few seconds. Because there are many types of video cards and monitors out there, this process can take a little while to complete.

Unfortunately, sometimes Ubuntu can’t autodetect what video settings to use, especially with some of the newer, more complicated video cards. If this happens, Ubuntu reverts to a default, safe X.Org configuration. The safe configuration assumes a generic video card and monitor and usually will produce a graphical desktop, although not at the highest resolution possible on your system.

If this happens in your installation, don’t worry. Usually you can use the Screen Resolution utility to set the proper video mode for your setup. If all else fails, you can manually enter the settings in the X.Org configuration file.


Source of Information : Wiley Ubuntu Linux Secrets

The X Windows System

Before we dive into the details of working with the video display in Ubuntu, it helps to get a little background on how Linux generally handles video. If you run the Ubuntu server, or if you run your Ubuntu workstation in text mode, there’s not much involved for Ubuntu to interact with the video card and monitor. By default Ubuntu can use just about any video card and monitor in text mode to display 25 lines of 80-column text. This feature is built into the Ubuntu Linux software so that it can directly send text to the monitor at all times.

However, when you use the graphical mode on your workstation, things are a bit different. Instead of directly sending text to the monitor, Ubuntu must be able to draw lines, shade colors, and manipulate images. To do that, Ubuntu makes use of a special type of software called X Windows to interface with the video card and monitor.



What Is X Windows?
Two basic elements control the video environment on your workstation:
• The PC video card
• The monitor

The Ubuntu operating system must interact with the video card in your PC to produce the graphical images for your desktop to appear and to run graphical applications. The video card controls how to draw the images on the monitor display, what colors are available to use, what size of display area you can use, and at what speed the system can draw the images.

The video card must be able to interact with the monitor to display the images sent by Ubuntu. There’s wide choice of monitors available these days, with a wide variety of features, from standard old-style, picture-tube monitors to modern flat-screen plasma monitors. The combination of the video card features and monitor features determines the graphics capabilities of your workstation. Ubuntu needs to know how to use and exploit these features to produce the best possible graphics for the desktop and applications. Given the wide variety of video cards and monitors available, it would be difficult for the GNOME desktop developers to have to code the features found in GNOME for every possible video card and monitor environment available. Instead, the X Windows software helps do that.

The X Windows software operates as an intermediary between the Ubuntu system and the input and output devices connected to the workstation. It’s responsible for controlling the graphical environment so that GNOME doesn’t have to support different types of video cards and monitors. Instead, the X Windows software handles all of that, and the GNOME software has to interact with just the X Windows software to display images on any type of video card and monitor combination.

Besides dealing with the video card and monitor, X Windows also handles any input devices attached to the workstation, such as the keyboard and mouse. It’s the main clearinghouse for all interaction for the desktop environment.

Because the X Windows software handles all of the input and output functions for the Ubuntu workstation, it’s important to ensure that the X Windows software is working properly. It must know the type of input and output devices it’s communicating with so that you can interact with your desktop.

The X Windows software is actually a specification of how to interact in a client/server methodology, serving the input and output devices to Ubuntu applications. Two popular X Windows implementations are currently available in the Linux world.

Source of Information : Wiley Ubuntu Linux Secrets

The XSane Work Area

The XSane work area consists of four separate windows:
• Main window: Contains selections to set the scanning mode and features used in the scanning process.

• Histogram window: Shows the color-density spectrum of the image.

• Preview window: Displays a low-resolution scan of the image and allows you to alter the scan area.

• Viewer window: Displays the final scanned image and provides some rudimentary image functions.

Each window provides access to specific functions of the scanning process, as detailed in the following sections.



The Main Window
XSane’s Main window interface depends on the mode you are working in. There are six different modes that the XSane interface uses. These modes are set with the drop-down box in the upper-right corner of the page (next to the sight icon).

The XSane Operation Modes
Viewer
Sends the scanned image to the Viewer window. You can set the default filename, file type, and a counter increment for storing multiple files.

Save
Saves the scanned image to a file using the filename and type specified.

Copy
Sends the scanned image directly to the specified printer.

Multipage
Collects multiple scans to combine into a single project that can be saved in Post-Script, PDF, or TIFF format.

Fax
Sends the scanned image directly to faxing software, if installed.

Email
Sends the scanned image directly to an email software package


The Main window also allows you to change settings for the scan, using a series of dropdown boxes, sliders, and buttons:
• Scanner Hardware Type: flatbed or autofeeder
• Scanning Color Mode: color, grayscale, or black and white
• Image Adjustments: brightness, contrast, and color
• RGB Default: red, green, and blue value enhancements
• Negative: invert black/white images, used for scanning negatives
• Auto-enhancement: automatically determine the best values for colors
• Enhancement Default: resets image adjustments to the default values
• Restore Enhancement: retrieves stored enhancement settings
• Memory: stores the set enhancement values in memory

Each of the modes allows you to set the color features of the scanning process so that you can fine-tune the results of the scan. The Histogram window also helps you out here.



The Histogram Window
The Histogram window (as seen back in Figure 15-9) displays a color spectrum of the color densities contained in the image. There are two histograms in this window. The top histogram displays the color densities of the raw image directly from the scanner. The bottom histogram displays the color densities after the color enhancements set in the
Main window have been applied. The Histogram window provides simple controls for viewing the histograms. The four sliders in the middle between the histograms allow you to define the black, white, and gray points in the histogram. The buttons under the histograms allow you to single out a single color component (or the intensity for the I button). The fifth button in the row defines whether the histograms are drawn with pixels or lines, and the LOG button defines whether the densities are displayed as linear or logarithmic values.



The Preview Window
The Preview window allows you to adjust the scanning settings before making the final scan. It consists of a viewing area to preview the scanned document as a low-resolution scan, a toolbar at the top of the window with buttons for various features, and some selection buttons at the bottom of the window to customize the scanning settings.

To perform a preliminary scan, click the Acquire Preview button at the bottom of the Preview window. XSane performs a low-resolution scan of the document and displays it in the Preview window viewing area.

The buttons in the toolbar, from left to right, are
• Batch scan add area: Add the selected area on the preview image to a list of areas to scan.
• White pipette: After clicking this button, use the mouse pointer and left-click on an area in the preview image that is considered white. This value is used to adjust the automatic color settings.
• Gray pipette: After clicking this button, use the mouse pointer and left-click on an area in the preview image that is considered medium gray. This value is used to adjust the automatic color settings.
• Black pipette: After clicking this button, use the mouse pointer and left-click on an area in the preview image that is considered black. This value is used to adjust the automatic color settings.
• Unzoom: Return the preview area to the original scan area.
•Zoom out: Increase the preview area by 20 percent.
•Zoom in: Decrease the preview area by 20 percent.
•Select zoom area: Use the mouse to select an area to zoom.
•Undo zoom: Remove the previously set zoom area.
•Autoselect: Select the part of the image to edit.
•Autoraise: Click an image to raise it to the forefront.
•Select visible area: Select the visible area in the preview for scanning.
•Delete preview image cache: Preview images are cached to allow the undo function.
Click this button to remove any previously previewed images.

Besides the toolbar buttons there are several buttons at the bottom of the Preview window that affect the operation of the scan:
•Preset area: Select an area of the preview image to be used as the maximum scanning area. This value is relative to the size of the scanner bed.
•Rotation: Select a rotation angle and axis to use to rotate the scanned image.
•Aspect ratio: Define a width:height aspect ratio to set for the scanned image. This option limits the selection frame size because the specified ratio is maintained.
•Acquire preview: Perform a low-resolution preview scan using the Preview window settings.
•Cancel preview: Stop the preview scan.
•RGB settings: Adjust the red, green, and blue values of the pixel pointed to with the mouse pointer.
•Magnifier: Magnify the area directly around the mouse pointer to allow more precise selection of scan and edit areas. XSane allows you to perform quite a bit of customizing in the Preview window before you make the final scan of the image. This capability helps you avoid having to rescan an image until you get it right.



The Viewer
The Viewer window displays the final scanned image when you select the Scan button and allows you to perform some rudimentary operations on the image before saving it. The Viewer window contains a toolbar above the scanned image that provides access to the necessary functions. The toolbar buttons available are
•Save image: Save the image to disk, specifying the file type and name.
•OCR: Attempt to read any text on the image and save in a text file.
•Clone image: Open another Viewer window with a copy of the scanned image.
•Flip: Reverse the image in the Viewer window.
•Despeckle image: Remove spots from the scanned image.
•Blur image: Apply a blurring feature to the scanned image.
•Scale image: Change the size of the image.
•Rotate image: Three buttons that allow you to rotate the image 90, 180, and 270 degrees.
•Mirror image: Two buttons that mirror the image using the horizontal or vertical axis.
•Zoom: Zoom in to or out from the image in the Viewer window.

If you set the filename and extension of the file in the Main window, the Viewer automatically saves the image using that file type and name. If not, the Viewer provides a Save As dialog box that allows you to set these values. XSane supports saving images using the file types.

XSane provides a wide selection of standard file formats for storing your image file. Images saved as PDF files are compatible with Adobe Acrobat Reader applications on the Microsoft Windows platform, which is a great feature of XSane.

Source of Information : Wiley Ubuntu Linux Secrets

Scanning a Document in Ubuntu

Now that you have XSane set up to use your scanner, you’re ready to start scanning documents and saving them on your workstation. Here are the basic steps to scan and save a document:

1. Start XSane from the Panel menu (Applications -> Graphics -> XSane Image Scanner).

2. Place the document you want to scan in your scanner. Some scanners use an autofeeder, while others (known as flatbed scanners) have you place the document on the glass scanning surface and close the cover.

3. Click the Acquire Preview button in the Preview window of the work area. The preview function performs a low-resolution, quick scan so you can determine the basics of how the scanned image will look.

4. Select a mode for the scan in the Main window. XSane allows you to scan a document to a file, to a printer, to a fax program, or to an email message.

5. Make any necessary adjustments to the color settings in the Main window and, if you don’t want to scan the entire document, select the area to scan in the Preview window. The XSane application provides many settings for customizing the scanning process.

6. Click Scan in the Main window of the work area. The Scan button performs the scan as determined by the settings in the Main and Preview windows. When the scan completes, the scanned image appears in a new Viewer window.

7. In the Viewer window, click either File ➪ Save Image from the menu bar, or the green Disk icon at the upper-right corner of the window. Select the file type to use when saving the file. XSane supports JPG, PDF, PNG, PNM, PostScript, TXT, and TIFF file types.

8. Repeat the process to scan a new document, or close XSane by selecting File ->
Quit from the Main window menu bar.

Now that we’ve walked through scanning a document, let’s take a closer look at the various windows and features available in the XSane work area.

Source of Information : Wiley Ubuntu Linux Secrets

WINDOWS LIVE ESSENTIALS

Windows Vista's Mad, Calendar, Photo Gallery and Movie Maker are missing from Windows 7 but there's no need to panic. They're all available - new and improved – as separate download


WINDOWS LIVE MAIL, CALENDAR AND CONTACTS
Live Mail has been considerably streamlined: net only can you now sign up to email services such as Gmail without having to enter server addresses, but the whole app looks far more attractive. A Quick Views mode lets you filter email using predefined criteria, such as "Unread email" and 'Unread from contacts". And it's more secure than before, with phishing alerts built in. Microsoft has also gone back on its decision in Vista to split Mail and Calendar. Both launch in the same window, and there's more integration' you can now add emails to appointments with a single click, and the "Add contact" option is more obvious. The Contacts application still launches in a separate window, but it benefits from better integration too, and is now linked directly to your Windows Live contacts. Anyone you add here will be available to Messenger - and vice versa - as well as to Windows Live webmail and Windows Mobile users.


WINDOWS LIVE MOVIE MAKER
Perhaps the most significant overhaul of all the previously bundled apps is Movie Maker. The original interface has been completely ditched in favor of a hybrid timeline/storyboard view that's easier to use. It's still no replacement for a dedicated video-editing tool such as Adobe Premiere Elements 8, with support for just the one video and audio track, but there's enough here to enable most amateur videographers to produce quick, polished home movies with the minimum of effort. I There's far wider support for the latest HID formats than: before, including AVCHD, and with more output options too you can produce a straightforward WMV file, for instance, but also burn a DVD or upload footage directly to YouTube. Finally, there's a selection of special effects and a Brightness tool for lifting dull footage, while the AutoMovie tool speeds up the process, automatically fitting your clips and photos to music.


WINDOWS LIVE WRITER
Writer- is a brand-new application designed purely for offline blog posting. You could be forgiven for wondering what such an app would add, especially since most blog services' online interfaces are so usable these days. He obvious and biggest, advantage is that you don't need to he online at all to write and prepare your blog post. You can simply pop in to Writer, add tags, pictures, links and movie s while you're between Internet cafes - and once you've got yours elf web access, all you need to do is hit Publish. The most wonderful thing about Writer is that, once you pointed it at your blog and supplied a username and password, it analyses the website, downloads graphics and other page elements, and lets you preview your blog offline too, so you can be sure the layout is just right. It works brilliantly a worth addition to the Windows toolkit.


WINDOWS LIVE PHOTO GALLERY
The one application in the collection we're not completely convinced by is Photo Gallery. The reason? Gougle's free Picasa application is better - better at searching, browsing, organising quick edits and sharing. The one major advantage of the Photo Gallery is that it makes simple photo-editing and tagging facilities available a view that fits far more naturally into the Windows 7 way doing things. There's also that tight integration with other Windows applications and services again, allowing you to photographs from published albums to Writer blog posts, for instance. Like Picasa. It is also offers face recognition. But with Google Picasa offering advanced features such as geotagging, a more streamlined inter face and far more options for editing, printing and sharing photos, we won't moving away to Photo Gallery just yet.

Source of Information : PC Pro December 2009

The Windows 7 sham

CONSUMERS HOLDING "FREE"WINDOWS 7 UPGRADE VOUCHERS ARE IN FORA SHOCK WHEN THEY COME TO REDEEM THEM FINDS TIM DANTON

People who bought Windows Vista PCs in recent months may have been reassured to find an upgrade voucher for Windows 7 waiting in the box. What many of those voucher holders don't realize is that the "free" upgrade voucher may end up costing them ￡30. The Windows 7 Upgrade Option programme is designed to prevent PC sales from grinding to a hail in the run-up to its release, by offering buyers of Vista PCs a smooth upgrade path to Windows 7. However, it seems both Microsoft and selected PC vendors are using it as an excuse to squeeze a little more revenue out of PC buyers. PC Pro investigated the upgrade policy of 12 leading PC manufacturers. No fewer than ten of them are demanding extra payments from customers before they send out Windows 7 upgrade discs. Fujitsu, at €36 (around ￡32), is the most expensive. Four other leading PC manufacturers - HP, Lenova, Sony and Toshiba - are all demanding in excess of ￡20, while Dell declined to divulge how inudi it would be charging customers. Why do PC makers feel the need to charge customers who've recently paid hundreds - if not thousands of pounds - to simply send out a new disc? Many of the PC manufacturers blame extra shipping and handling costs. Others claim to be throwing in additional extras for the fee. Toshiba, for instance, is also including a bundle of manufacturer specific drivers with the Windows 7 disc, as well as sending the package via recorded delivery.

Other PC manufacturers are apportioning blame to Microsoft, claiming the software giant is itself cashing in on the Windows 7 upgrades. PC Specialist's John Medley told PC Pro that: "since 26 June 2009, Microsoft has been selling two different SKUs through distribution for each version of Vista. One Wit includes the upgrade voucher and one doesn't. The SKU with the upgrade voucher is f10 extra." In the light of such information, the ￡20 charges for Windows 7 upgrades suddenly don't seem outlandish. But is
Microsoft setting its PC partners up for a fall, when customers suddenly realize they're going to be tapped for extra money for what, on the surface at least. appears to be a free upgrade? "We give manufacturers complete control over the prugrai rime," said Laurence Painell, Windows OEM & WGA product manager. "Obviously, they have varying levels of cost, whether it be in support, procurement or distribution costs associated with the nature of the product they're shipping, and as such it really is their decision as to how much they charge their customers and the process they go through." Microsoft's Windows 7 Upgrade Option website (www.mIcrosoft.com/windovvsibuy/offersiu pgrade.aspx) astutely avoids using the ward "free" in conjunction with the offer. Some of Microsoft's PC partners aren't sn careful, however. Lenovo's site brashly boasts of a "FREE Windows 7 Upgrade program", before using the obligatory asterisks to explain that a handling fee applies. Other PC retailers visited by PC Pro are also bandying the word "free" around as part of their in-store promotions. "Our recommendation to consumers is very much to check with the retailer or the manufacturer at the time of purchase to understand exactly what the implications of the upgrade programme are," Microsoft's Paine!! advised. Nat all PC companies are forcing customers to pay more for the upgrade.

British PC manufacturers Mesh and Chillblast are both dishing out the discs for free, which will be sent directly from a Microsoft-approved partner. Yet, some people question whether the companies that are up front about the charges are actually any gulltler than Mesh and Chillblast. "Perhaps the ones who are charging ￡20 plus are the ones who are passing on the cost transparently to the customers who want the upgrades. Whereas others may just be burying the cost, meaning that customers who aren't using these upgrades are still footing some of the bill (for example, by putting flO on the cost of every PC sold, which is easy to do when products change often and are made of a variety of components)," argued PC Pro forum member halsteadk. Whichever way you view the ethics of applying extra charges for the Windows 7 upgrades, it's still likely to stick in the craw of anyone who has to foot an unexpected bill - especially given Microsoft's recent announcement that students will be able to download the full version of Windows 7 Professional for only f30 - ￡7 less than Fujitsu's upgrade discs. Why couldn't Microsoft at least have provided the option of a free Windows 7 download and product key to all those enrolled in the upgrade scheme, thus avoiding the on seemly costs associated with distributing physical media? The software giant's unfortunately knack of turning a positive into a negative shows no sign of diminishing.

Source of Information : PC Pro December 2009

INSIDE INTEL'S TECH SHOWCASE

PC Pro's technical editor Darien Graham-Smith flew out to San Francisco to catch up with all the latest developments at the Intel Developer Forum. Here are the highlights from this autumn's expo.


22nm processors
While delegates widely anticipated the unveiling of processors based on the 32nm manufacturing process, Intel chief executive Paul Otellini sprung a surprise by wheeling out the company's first 22nm processor. Although only test chips have been Manufactured, Intel claims to have successfully produced both RAM and logic transistors putting the chip giant some distance ahead of the technology curve. According to Intel's roadmap, 22nm CPUs won't hit the mainstream until 2012, but the announcement shows the company isn't resting on its laurels after the success of Core 17.


Four-screen laptop
The show wasn't all about silicon, though, and one of the most enticing demonstrations revolved around a laptop sporting four displays, codenamed Tangent Ray. Aside from the standard 15in screen, the laptop also houses three smaller touchscreen OLEO screens above the keyboard. These were used to display a music playlist, a photo slideshow and a calculator, but Intel claims they can be used for anything you'd use the principal monitor for. Unfortunately, there's no word on whether the laptop will ever find its way out of the company's labs.


Ubuntu Malin Remix
One technology that's definitely making waves beyond Intel's halls is Moblin. The open source 0S has been developed to Eake advantage of Atom-based machines, and will form the core of Ubuntu Moblin Remix - a stripped-down version of Ubuntu aimed at netbooks and other smaller-screen devices. Dell has already announced it will begin shipping versions of its Mini 10v netbook running the 05, although it hasn't yet specified a timeframe. Given that the current release is labelled a "Developer Edition", we may be waiting some time.


Atom app store
Intel's netbook dominance meant Atom was always going to be high on the agenda. Despite this, news that the chip giant is opening an app store featuring applications optimised to run on the low-power processor caught everyone cold. The chip giant is releasing an SDK to spur app development, and will offer developers 70% of any revenue earned from their creations. According to Paul Otellini, the aim is to allow apps developers to "write once, run on all devices". "Look at the opportunity around netbook volume - we need a better app environment. People want to do more on them than just run legacy applications," he said. Hardware manufacturers will also be able to create storefronts to sell the applications, with Acer, Asus and Dell already signed up.

Source of Information : PC Pro December 2009

iPod Nano and Zune HD: Capable Media Players

OTHER THAN THE ability to play music and video, the new iPod Nano and the Zune HD share few similarities. The iPod Nano is more of a secondary player for commutes or the gym, and its new video camera makes it ideal for YouTube clips. Th e Zune HD, in contrast, is for the media junkie, offering a higher capacity and HD video playback.



Apple iPod Nano
Measuring 3.6 by 1.5 by 0.24 inches and bearing a 2.2-inch display, the 1.3-ounce fifth gen Nano ($150 for 8GB, $180 for 16GB) comes in a rainbow of colors, encased in polished anodized aluminum. The finish is attractive, but susceptible to smudges and fingerprints. Among the new features is an FM radio tuner (at last!). Though the FM radio isn’t particularly innovative (we saw this feature on the firstgen Zune), it can pause and play radio, and it works well. Thanks to its integration with iTunes, the Nano has unbeatable audio and video features. Genius Mixes, which group your music by a common characteristic, generate directly on the Nano when you sync from iTunes. Audio sounded clean but somewhat tinny through the included earbuds. In the PC World Labs’ audio-quality tests, this Nano scored similarly to its predecessor, receiving a rating of Superior.

The video camera is a positive addition. Th e lens placement is awkward, however, and I found that holding the sliver-thin Nano by its edges was difficult. Gripping it at the bottom doesn’t work well either, as the lens sits at the bottom of the device when you hold it vertically. Video shot outside was bright and sharp. But since the Nano has no contrast or brightness controls, my indoor clips were fuzzy, dark, and grainy. The mic picked up sound adequately. The 640-by-480-pixel VGA footage is compatible with streaming-video sites, and it works natively in iTunes. Watching video on the Nano itself is surprisingly enjoyable. Still, viewing videos on a device this small takes some getting used to, and the rounded screen attracts quite a bit of glare.



Microsoft Zune HD
The Zune HD marks a huge mprovement from last year’s
odel in speed, video quality, usability, and design. But while it is priced competitively
($220 for 16GB, $290 for 32GB), you’ll have to pay more to take full advantage
of all of its features. Physically, the Zune HD represents a complete make- over. It measures 4.0 by 2.0 by 0.3 inches and weighs 2.6 ounces. A gorgeous, 3.3-inch, multitouch OLED display dominates the face. Microsoft has added an HD radio receiver. HD radio delivers cleaner sound than analog FM does, and lets stations broadcast extra channels; you can also tag and download songs from the Zune Marketplace. To fully enjoy the Zune HD’s high-def video capabilities, you’ll have to pay $80 for the HDMI docking station. The Zune HD supports 720p HD fi les, so you can play videos via the dock on your HDTV. Video on my HDTV had bright and accurate colors, smooth transitions, and little pixelation. Video playback on the Zune HD itself was impressive, too. Audio quality was good, but you’ll want to ditch the included earbuds. With better headphones, songs sounded rich and clean. Microsoft has optimized the interface for the multitouch display. Th e new Quickplay item displays your most recently added content and history, and lets you pin your favorites. The Zune 4.0 PC soft ware has its own splashy Quickplay page. You can’t sync the menus, however; favorites you add to your Zune won’t carry over to your PC. Another new soft ware feature is SmartDJ, which, similar to Genius Mixes, creates a playlist from songs in your library and on the Zune Marketplace. You have to buy the Zune Pass ($15 per month), however, to enjoy the Zune Marketplace content.

Source of Information : PC World December 2009

Second-Gen Flip Video MinoHD: The Best Pocket Camcorder

THE SECOND-GENERATION Flip Video MinoHD doesn’t represent a huge jump in specs and features, although changes in the new model from the previous version include a doubling in storage capacity (from 4GB to 8GB), revamped video soft ware, an HDMI-out port, and the end of the line for the Pure Digital brand (Cisco purchased the company in March, and “Flip Video” is now the brand name). The stars of the show are the vastly improved build quality, the unit’s bestin-class low-light video, and the sheer aesthetics of the device. Unlike the plasticky, cheap feel of previous Flips, this one feels a whole lot sturdier and looks a whole lot better (the brushedmetal faceplate and redesigned USB connector even make the new MinoHD look like an Apple product). Video quality has improved, as well. Like the first-gen MinoHD, the new model shoots 720p high-definition MPEG-4 video at 30 frames per second; clips are smoother and sharper than those produced by its competitors. Flip cams have traditionally smoked the competition in taking low-light video, and the new MinoHD ups the ante even further: The footage it takes in low-light conditions is clearly at the head of the pocket-camcorder class, rivaling and even surpassing the low-light video of $1000-and-up HD camcorders. Similar to earlier models, the new MinoHD has a flip-out USB 2.0 connector which pops up, switchblade-style, from the top of the device. (It also sounds more like a switchblade in this version, since the redesigned connector is now entirely metal.) This one of two connectors on the device; the new MinoHD has a mini-HDMI port on the bottom of the unit for watching videos on an HDTV set, which is another addition over the previous MinoHD. (You get no HDMI cable in the package, however.) The revamped FlipShare soft ware, which installs and launches when you plug the camcorder into your PC, now supports direct-to-Facebook uploads and adds a feature called MagicMovie that lets you enhance your footage with transitions, music, and more. The sum of all these parts is arguably the best HD pocket camcorder you can buy now. Although Kodak’s 1080pshooting, digitally stabilized Zi8 is still a notch above the new Flip in brightlight video quality, frame-rate controls, and overall features, it has some nagging usability issues. The new Flip MinoHD beats it in low-light footage, usability, durability, and design.

Source of Information : PC World December 2009

HP’s Slickest Laptop Is Designed to Stir Envy

THE HP ENVY 13 is a PC answer to Apple’s MacBook Pro: It’s similarly sleek but costs a bit more, starting at $1699 (our review unit is $1799). It comes with a 2.13GHz Intel Core 2 Duo SL9600 CPU, 3GB of RAM, and an ATI Mobility Radeon HD 4330 discrete GPU. The laptop is 12.6 by 8.5 by 0.8 inches and weighs 3.1 pounds. It earned a nice WorldBench 6 score of 94. You can play HD video on the crisp, glossy 13.1-inch backlit LED screen—but reflections on it will be distracting. The Envy has high-tech Beats audio, but you’ll need headphones or earbuds to appreciate it. Though the touchpad’s multitouch functionality works, the mouse buttons are poorly placed. The keyboard is fine. The notebook has a couple of USB 2.0 ports, an HDMIout, an SD flash-card reader, and a headphone/mic jack. Missing are ports for wired ethernet and VGA (you do get Bluetooth and 802.11n Wi-Fi). And it has no optical drive—you must buy an external one (starting at $100 for a DVD-ROM version). A helpful six-cell battery slice goes for another $100. We give HP nods for smart design overall, and a promise of premium support. (You even get a 2GB SDHC card that holds the manual.) The Envy 13 has a lot of eyecatching touches and is a good machine for people who have money to burn.

Source of Information : PC World December 2009

The E-Book Explosion

As consumer interest in e-book readers approaches critical mass, the number of highquality models available is mushrooming.

THE E-BOOK universe is expanding rapidly. Amazon’s Kindles still off er the ultimate in wireless-transfer convenience, but other readers and e-book resellers are starting to compete on price and content—including hundreds of thousands of free books Amazon doesn’t offer. E-books have numerous benefits. Eliminating paper saves resources. E-book readers take up little room in travelers’ backpacks and purses, while storing the equivalent of a whole bookshelf.

You don’t have to go anywhere to buy or borrow an e-book title. For the vision-impaired, the ability to adjust font size can make the difference between being able to read a book and having to hope for an audio version. Some readers double as music players, and some even read books aloud. Unfortunately, the world of e-books is Balkanized, with multiple incompatible file formats and digital rights management (DRM) technologies, and devices with varying support for both. Books in the public domain are widely available in PDF and other standard formats. But copyrighted material is another story. Amazon’s current Kindles can obtain commercial e-books in Amazon’s AZW file format via wireless download only in the United States (in early October, however, the company announced a Kindle capable of downloading content in most countries). Meanwhile, Sony, which produces some of the classiest e-book readers around, is abandoning its proprietary BBeB e-book fi le format and shifting protected content in its e-book store to Adobe ePub, an e-book fi le format that book publishers and re - sellers have widely embraced. Whereas Adobe’s PDF reproduces a fixed image of a page, ePub permits reflowing of text to accommodate different fonts and font sizes. Adobe off ers a DRM technology called Adobe Content Server 4. Sony and a number of other online bookstores— most notably Borders—sell commercial titles in ePub/ACS4 format, and some libraries let patrons check out ePub books. As of early October, 17 e-book readers supported ePub and ACS4, making that combination the closest thing the industry has to a standard for DRM-protected books. Aside from the Amazon Kindles and Foxit’s eSlick, all of the e-book readers in this review support ePub/ACS4.



Sony Reader Touch Edition (PRS-600)
Sony’s new flagship e-book reader offers something we haven’t seen in previous Sony Readers: a touchscreen and stylus for navigating and for creating drawings and handwritten notes. Whether this innovation enhances the e-book experience is open to debate, but the overall quality of the product is not: Except for its lack of wireless connectivity for purchasing books without connecting to a PC, the Touch Edition is a worthy competitor to Amazon’s Kindles. This reader looks like a refined version of Sony’s previous reader, with a 6-inch, 8-grayscale E Ink screen framed by a metallic case (available in silver, black, or red). Beneath the display are five thin silvery bar-shaped buttons for turning pages and accessing menus. The Touch Edition lets you create text memos (via an on-screen keyboard), listen to unprotected MP3 and AAC music, view images, and set up a slideshow. The MP3 player was the best on any e-book reader I tried, with reasonably strong audio through earphones plugged into the Touch Edition’s standard headphone jack. It includes repeat/shuffle options, and you can play the music while you read. The reader comes with a dictionary and lets you annotate your books and documents. The Touch Edition is a topnotch e-book reader. Th ough pricey at $300, it’s well de -
signed and feature-rich.



Amazon Kindle DX
The Kindle DX looks surprisingly lean and elegant. On the device’s front is a spacious 9.6-inch E Ink display that can show 16 shades of gray (as can the Kindle 2). At 7.2 by 10.4 by 0.4 inches and 18.9 ounces, the Kindle DX is the largest and heaviest of today’s e-book readers. Like the Kindle 2, it has a keyboard (for annotations and for searching for books in Amazon’s Kindle store through the built-in wireless connection), but typing on it is awkward. In the United States you can shop for and download books from the device without connecting to a PC (only the just-announced global version of the Kindle 2 lets you download content elsewhere). Though the DX’s spacious screen and skinny profile are big pluses, the device is unlikely to succeed as a newspaper or magazine replacement; it’s too heavy for that, and its E Ink display lacks the color and visual appeal that modern print publications possess. The DX’s high price is likely to turn off some potential customers as well: At $489, it costs more than some full featured laptops.



Amazon Kindle 2
The Kindle 2 is a sleek, curved tablet that you can hold easily in your hands. Like other Kindles, it offers easy access to Amazon’s Kindle store through Sprint’s 3G wireless network (at no extra cost to users), so shopping for books is a breeze. But Amazon doesn’t make available the hundreds of thousands of free e-books you can get from other stores. Its polished design looks great, as does its 6-inch, 600-by-800-pixel E Ink screen. Text is sharp, and images are crisp. But the Kindle 2’s stumpy five-way navigation joystick feels stiff and sits awkwardly near the right bottom edge. Still, the QWERTY keyboard below the display is surprisingly usable, with circular keys that are easy to press. Even though its extras are limited to a text-to-speech capability, a basic MP3 player and a Web browser, the Kindle 2 stands as a good reader’s companion overall.



Sony Reader Pocket Edition (PRS-300)
The Pocket Edition is about as inexpensive as e-book readers come: $199 for a slim gadget with a 5-inch, 8-grayscale E Ink screen. It lacks extras that some competitors
offer, but its topflight design and usability more than compensate for the missing features.
Like previous Sony Readers, the Pocket Edition has a metal case (most competitors use some sort of plastic), which may explain why it tips the scales at nearly half a pound. But the silvery case felt great in my hands, and the reader’s controls are simple and intuitive.
Document file format support is limited to unencrypted BBeB, ePub, PDF, TXT, RTF, and Microsoft Word (.doc) files, plus (on commercial books) encrypted BBeB, ePub (with Adobe Content Server 4 DRM technology), and PDF files. The Pocket doesn’t support image or HTML files, and you don’t get a dictionary. Reading on the Pocket Edition is easy and intuitive: Pages looked good and flowed neatly, and page turns were responsive—on a par with those of other devices. Overall, the Pocket Edition is appealing, not just for people on a budget (after all, the Kindle isn’t a lot more expensive), but for anyone who wants a small, no-frills e-book reader to carry in a purse or backpack.



Interead Cool-ER
The $249 Cool-ER strives to distinguish itself from the black-and-gray competition, and for the most part it succeeds. Skinny (0.4 inch thick), lightweight (6.2 ounces) and available in eight cheery colors, this e-book resembles an overgrown iPod—not a bad role model for industrial design. The only items visible below the 6-inch screen are the device’s logo and a round, iPod-esque four-way navigation/selection wheel, which you use to navigate through menus and turn pages. Unfortunately, because the button is quite stiff , using it is unnecessarily arduous. The Cool-ER’s display employs the same E Ink technology that Kindles, Sony Readers, and other e-book readers use. The Cool-ER adopts the 8-grayscale version, operated by a 400MHz Samsung ARM processer. You can transfer content only via the USB cable, but a wireless model is due next year. The Cool-ER supports about a dozen fi le formats, including ePub, HTML, PDF, Rich Text, and three popular image formats; ePub with Adobe Content Server 4 digital rights management soft ware is the primary format for commercial e-books, which you can buy at CoolerBooks.com (its available library isn’t huge) or at other sites that support ePub and ACS4. The built-in MP3 player lets you play music while you read, but it’s a barebones audio player. Annoyingly, the headphone jack port doesn’t accept standar mobile 3.5mm jacks. You’ll have to get a 2.5mm adapter to use it with most current headphones or phone headsets (the Cool-ER comes without earphones). A little polish (and a better four-way navigation wheel) would improve the Cool- ER’s usability. But for the price, it’s not a bad deal.


Source of Information : PC World December 2009

Using 3-D Cards in Ubuntu

In the past, one of the weaknesses of the Linux environment was its support for advanced video games. Many games popular in the Microsoft Windows world use advanced graphics that require specialized 3-D video cards, which Linux systems couldn’t support. In the past, specialized 3-D video cards were notorious for not working in the Linux environment because video card vendors never took the fledgling Linux market seriously. However, things are slowly starting to change. Two major 3-D video card vendors, ATI and NVIDIA, have released Linux drivers for their advanced products, allowing game developers to enter the Linux world. There’s a catch, though. Both ATI and NVIDIA released Linux binary drivers but not the source code for their 3-D video cards. A true open-source project must include source code for the binary drivers. This has caused a dilemma for Linux distributions. A Linux distribution that includes ATI or NVIDIA binary drivers violates the true spirit of open-source software. However, if a Linux distribution doesn’t provide these drivers, it risks falling behind in the Linux distribution wars and losing market share.


Ubuntu 3-D Support
Ubuntu has decided to solve this problem by splitting the difference. Ubuntu can detect
ATI and NVIDIA video cards during the installation process and can install the proprietary binary drivers to support them. Ubuntu calls these restricted hardware drivers. Although Ubuntu supplies restricted hardware drivers, it doesn’t support them in any way. When you first log into the desktop after installation, Ubuntu displays a warning dialog telling you that restricted drivers have been installed. After the installation, an icon appears on the top panel, indicating that a restricted hardware driver has been installed and offering the option of removing the restricted drivers and replacing them with lesserquality open-source drivers.


As with all things in the open-source programming world, there are current efforts to create open-source versions of many restricted hardware drivers. The Nouveau project is attempting to create a high-quality, open-source driver for operating NVIDIA cards in 3-D mode. At the time of this writing they’ve completed drivers for operating NVIDIA video cards in 2-D mode but haven’t finished the 3-D features. As Ubuntu progresses through new versions, it’s possible that a video card that once required a restricted driver will have an open-source driver in a newer distribution.

As with all things in the open-source programming world, there are current efforts to create open-source versions of many restricted hardware drivers. The Nouveau project is attempting to create a high-quality, open-source driver for operating NVIDIA cards in 3-D mode. At the time of this writing they’ve completed drivers for operating NVIDIA video cards in 2-D mode but haven’t finished the 3-D features. As Ubuntu progresses through new versions, it’s possible that a video card that once required a restricted driver will have an open-source driver in a newer distribution.

Source of Information : Wiley Ubuntu Linux Secrets

Are Flash Cookies Devouring Your Privacy?

Small Flash files can track your online movements, and they don’t vanish when you delete normal tracking cookies.

EVEN IF YOU delete normal tracking cookies regularly to evade tracking by snooping sites and eager advertisers, little-known Flash cookies may be making an end run around your attempts to preserve your privacy. Flash cookies (also known as local shared objects or LSOs) can save certain Adobe Flash–related settings—storing preferences for watching Flash video on a certain site, for example, or caching a music file for better playback. But Flash cookies can also store unique identifiers that track the sites you visit, much as regular tracking cookies do. Deleting the regular cookies on your machine via a standard browser option such as Clear Private Data¨Cookies (in Firefox) or Tools¨ Delete Browsing History¨Delete cookies... (in Internet Explorer) doesn’t affect Flash cookies, which are stored elsewhere on your PC.



Flash Cookie Research
A recent study (find.pcworld.com/63930) of Flash cookies and their use reports that even the private browsing modes in the latest browsers won’t hamper LSOs. Students and researchers at the University of California, Berkeley, and at other universities found that a number of sneaky online actors use Flash cookies to re-create regular tracking cookies that users delete. According to the study, more than half of the top 100 Web sites used Flash cookies, and third-party advertisers tended to be behind the underhanded cookie re-creation effort. If you don’t want your privacy preferences to be ignored, you can try a couple of options. If you use Firefox, you can install an add-on called Better Privacy (find.pcworld.com/63931) that displays a summary of your current LSOs and lets you arrange to delete Flash and regular cookies automatically whenever you stop or start the browser. It works well for me.



Flash Player Settings Box
If you don’t use Firefox, you’ll have to dig into the settings box at fi nd.pcworld.com/63932, which lets you change settings for the Flash Player on your system. If you want your computer to prompt you for permission to proceed whenever a site wishes to store a Flash cookie on the PC, move the Global Storage Settings slider bar all the way to the left (from ‘100KB’ to ‘None’). To disable LSOs, check the Never Ask Again box (doing so is likely to prevent many sites that use Flash content from working correctly). Likewise, unchecking the ‘Allow thirdparty Flash content...’ option could prevent advertisers from storing Flash cookies on your PC, but it may also prevent Flash video from working correctly on some sites (including 9 out of the 100 sites in the research report). To delete all existing Flash cookies— good or bad—click the Website Storage Settings tab at the far left of the Flash settings interface, and click the Delete all sites button at the tab’s base. To delete them individually, highlight an entry and click Delete website. Altering these settings once will cover any browser on that PC, according to Adobe. Longer term, the company is looking into allowing Flash cookie controls from the browser menu itself.


Source of Information : PC World December 2009

Banking Trojan Horse Hides Its Money Mules

TROJAN HORSES SUCH as Zeus and Clampi have been emptying bank ac - counts for years, but a devious new program tries to deceive investigators about where the money is going. First uncovered by Finjan Soft ware, the URLzone Trojan horse rewrites bank pages so that victims don’t know their accounts have been emptied. Its sophisticated command-and-control interface lets the bad guys preset the percentage of the account balance to remove. RSA Security researchers say that URLzone uses several techniques to spot machines run by crime investigators. Researchers typically create programs that mimic the behavior of real Trojan horses. When URL zone identifies one of these, it sends it bogus information, says Aviv Raff , RSA Security’s Fraud- Action research lab manager. Security experts have long published research on the inner workings of malicious computer programs such as URLzone, according to Raff . “Now the other side knows that they are being watched, and they’re acting,” he says. When URLzone spots a researcher’s program, rather than just disconnecting from the researcher’s computer, the server instructs it to transfer money— but not to one of the mules recruited to move cash overseas. Instead, it chooses an innocent victim—typically someone who has received legitimate money transfers from other hacked computers on the network, Raff says. So far, more than 400 legitimate accounts have been exploited in this way, according to RSA. The idea is to confuse researchers and to prevent discovery of the criminal’s real money mules. According to Finjan, the URLzone Trojan horse infected about 6400 computer users last September, clearing about $17,500 a day during that month.

Source of Information : PC World December 2009

Stymie Malicious Media, Network Attacks

Fix media-file flaws on PCs and Macs, and block Vista network attacks.

ESSENTIAL OS fixes are big this month. And fans of free software need to update their Firefox and OpenOffice copies. Apple’s QuickTime 7.6.4 update revises the program’s handling of .fpx, .mov, and .mp4 files on Windows XP, Vista, or 7, or Mac OS X (not Snow Leopard). In QuickTime, click Help¨Update Existing Software to ensure that you have version 7.6.4 (for details, see find.pcworld.com/63917). Microsoft’s patch plugs a security hole in the way Windows 2000, XP, Server 2003, Vista, and Server 2008 (but not Windows 7) process .asf or .mp3 media files. Microsoft’s bulletin (find.pcworld.com/ 63918) lists many vulnerable combinations of Windows Media Format Runtime and OS versions; run Windows Update to confirm you have the fix.


Network Flaws
Windows Vista and Server 2008 are vulnerable to several network-based security flaws. One, an SMBv2 file-sharing hole could let a remote attacker take over a machine. Microsoft hasn’t yet released a patch, but at find.pcworld.com/63919 the company has posted a “Fix It” for disabling SMBv2. File sharing should work, but it may be slow.
Microsoft did patch a flaw that malicious TCP/IP packets sent across a network might exploit. On Vista and Server 2008, that could mean a full takeover; on Windows 2000, Server 2003, and XP, a system crash is likelier. Microsoft won’t release a patch for Windows 2000 (see find. pcworld.com/63920) or XP (which by de - fault doesn’t accept the perilous packets). A network problem in the Wireless LAN AutoConfig Service (find.pcworld.com/63921) could let remote attackers “own” vulnerable Vista or Server 2008 systems. PCs that lack wireless cards or run other Windows versions are safe. A firewall will help block such Web-based assaults. Two more Microsoft patches correct critical flaws that might let code hidden on a Web page run commands on a vulnerable PC. One, in the JScript Scripting Engine (find.pcworld.com/63922), affects Windows 2000, XP, Server 2003, Vista, and Server 2008. The other involves the DHTML Editing Component ActiveX control (find.pcworld.com/63923), and is critical for Windows XP and 2000 only. Windows Update has both fixes, as usual.


Fixes for Free Software
If you use the OpenOffice productivity suite, update to version 3.1.1 or later to avoid a critical problem in how OpenOffice handles Microsoft Word documents. If you open a tainted .doc file, an attacker could take over your PC. Click Help¨Check for Updates to see whether you have the latest version (read more at find.pcworld.com/63924). Firefox versions 3.5.3 and 3.0.14 correct three critical flaws. Click Help¨Check for Updates, and see Mozilla’s Firefox 3.0 (find.pcworld.com/63925) and 3.5 (find. pcworld.com/63926) security advisories. Firefox 3.0 and 3.5 include a security feature that warns you to update Flash if your version is vulnerable; they also provide a link to the Flash download site. If you use Mac OS X versions 10.4 through 10.5.8, fire up Software Update to pick up Security Update 2009-005, which fixes image file, PDF file, or Web site holes (see find.pcworld.com/63929).

Source of Information : PC World December 2009

Phishers Dangle Some Brand-New Bait

IN SEPTEMBER 2009, some unlucky visitors at the New York Times Web site clicked on an ad that attempted to install malware. The advertisement displayed a popup window informing readers that their computer might be infected with a virus; only by purchasing a new antivirus product could they be sure of having a clean system. The Times later acknowledged the scam in a posting on its Web site: “Some NYTimes.com readers have seen a pop-up box warning them about a virus and directing them to a site that claims to offer antivirus software.… If you see such a warning, we suggest that you not click on it. Instead, quit and restart your Web browser.” Phishers and scammers use this and other new tactics to deceive unsuspecting victims.


Phishing 2.0
Phishing refers to an attempt to collect usernames, passwords, and credit card data by posing as a legitimate, trusted party. Often the deception in volves using e-mail sent from a trusted address. Originally, phishing applied to the banking and payment industry only, but now it also covers theft of log-in credentials to games, and personal passwords to social networks such as Facebook and Twitter. Most people wouldn’t reveal their social security number or mother’s maiden name at a strange site. Modern browsers and security software flag such content and ask you whether you’re sure you want to send it; some block it with a red-andblack warning label. So phishers have adopted new tactics.


Fake Antivirus Software an Emerging Problem
Rogue antivirus products are among the latest phishing instruments to appear, and many are quite convincing. Bearing names like Antivirus 2009, AntiVirmin 2009, and AntiSpyware 2009, they have interfaces similar to those of real antivirus apps. Some rogue antivirus products have their own keywords on search engines and cite fake reviews recommending them (see find.pcworld.com/63915 for one that I supposedly wrote). The rogue antivirus product that showed up on the New York Times site installed malware that, if executed, would have lowered the security settings in Internet Explorer, run executable files, and altered the system Registry. Such ac tions by phishing malware are fairly common. The real security apps knew it, too: Legitimate antivirus vendors AVG, Comodo, Kaspersky, McAfee, Microsoft, Nod32, and Sophos, (among others) detected this particular piece of malware within the first few hours.


Customer-Service Fakes
Another phishing gambit is a variation on an old scam: The crooks mass-mail a seemingly personalized e-mail message, ostensibly from a bank, containing a fake online chat option. In this “chat-in-the-middle” attack, as soon as the victim enters a user name and password at the designated online site, a chat window opens up and a scammer posing as a customer service rep at the bank requests additional personal information to confirm the identity of the account holder. By providing these details, the victim gives the thief crucial data.


Small Potatoes
Roger Thompson, chief research officer at AVG, says rogue antivirus products are common: “The bad guys are clearly making money at it.” Besides benefiting up front by selling the rogue antivirus product, they collect credit card information for future identity fraud. Jon Miller, director of Accuvant Labs, a security consulting firm that works with Fortune 500 companies and several U.S. government contractors, says that the New York Times incident isn’t unusual. Further, he notes that he has seen an upsurge in the use of malware tailored to customers of particular banks and other financial institutions.


Protect Yourself
AVG makes a free product called Linkscanner (find.pcworld.com/63911) that blocks new phishing attacks, yet allows users to safely view any site. For phishing attacks such as fake chat sessions and fake keywords, AVG’s Thompson says, users need to develop a healthy dose of skepticism, and learn how to kill the browser using Task Manager. That won’t stop Web-based exploits, but it will give you a way to defeat social engineering attacks.

Accuvant’s Miller recommends several common-sense antiphishing strategies:

¨Use a strong browser. According to Miller, Internet Explorer is the weakest browser, while Firefox and Google Chrome are relatively strong.

¨Use a malware resistant platform such as Mac OS or Linux. Though neither is impervious to attack, each is less likely to be targeted than the mainstream Windows operating system.

¨Use antimalware software; Miller says that his program of choice is Webroot Internet Security Essentials.

¨Update your software promptly and regularly, but don’t depend on updates as the sole way to guarantee your system’s security. As Miller observes, “malware tends to be ahead of the curve.”

¨Be cautious and vigilant when using high-profile social networking sites such as Facebook and Twitter.


Source of Information : PC World December 2009