How to add Items to the Start Button using Registry?

The best technique to edit the windows registry keys, always export or backup the whole windows registry keys on backup drive before editing. Because any mistake in Registry can cause serious problem in your computer to run properly.
Follow the given steps to change the Start button setting.
-First click on Start button then type Regedit in Run option.
-In Registry Editor go to left hand panel, and find HKey_Classes_Root / Directory / Shell
-Here Right click on Shell folder option and add any new key with descriptive name and Press Enter.
-Now Right click on that key and give the full path of that program you are interested to add in start button. For example if you want to add MS excel, then full path may be C:\program file\msoffice\msexcel.EXE.
-Now close all open programs and check the changes in your computer Start button.

How to add Items to the Start Button using Registry?

The best technique to edit the windows registry keys, always export or backup the whole windows registry keys on backup drive before editing. Because any mistake in Registry can cause serious problem in your computer to run properly.
Follow the given steps to change the Start button setting.
-First click on Start button then type Regedit in Run option.
-In Registry Editor go to left hand panel, and find HKey_Classes_Root / Directory / Shell
-Here Right click on Shell folder option and add any new key with descriptive name and Press Enter.
-Now Right click on that key and give the full path of that program you are interested to add in start button. For example if you want to add MS excel, then full path may be C:\program file\msoffice\msexcel.EXE.
-Now close all open programs and check the changes in your computer Start button.

Point to Point lease line configuration and tips

Point-To-Point Leased Line Implementation

Current configuration:
version 12.0
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname A-cisco
!
username B-cisco password 0 Jonn
!
interface SeriaIO/0
ip address 1.1. I.I 255.0.0.0 encapsulation ppp
ppp authentication chap
!
line con 0
transport input none
line aux 0
line vty 0 4
no login
!
end


Current configuration:
version 12.0
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname B-cisco
!
username A-cisco password 0 Jonn
!
interface SeriaIO/0
ip address 1.1. I.2 255.0.0.0 encapsulation ppp
ppp authentication chap
!
ip classless
no ip http server
!
line con 0
transport input none
line aux 0
line vty 0 4
no login
!
end

Extended IP Access Control List and Configuration

Extended IP Access Control List

RouterA(config)#access-list 103 remark stop telnet to router A whose source ip 1.1.1.2

RouterA(config)#access-list 103 deny tcp host 1.1.1.2 host 1.1.1.2 eq 23
RouterA(config)#access-list 103 permit ip any

RouterA(config)#int s0/0
RouterA(config-if)#ip access-group 103 in

RouterA#show access-lists
Extended ip access list 103
Deny tcp host 1.1.1.2 host 1.1.1.1 eq telnet(2 matches)
Permit ip any (160 matches)

How to eliminate the needless visual effects for better windows performance?

This tip will help you to increase the performance of your computer by eliminating the needless visual effects. By default windows XP gives you many options in the graphics fields to enjoy maximum graphics. For example, you can add pictures on folders and drop shadow on icon to give you better look but it will effect on the performance of your computer, especially on an older computer. Window XP has many default graphics which is not so useful for a common user, if you re-adjust these graphics then there is less effect on the user activities but the performance of computer will be increase tremendously. Here I will tell you how to choose:
To edit these settings, first you should log onto your computer with administrative rights.
-Click Start button and type sysdm.cpl in Run box then press Ok button for next.
-Here a dialog box will appear with the title "System Properties", select "Advanced" tab.
-Here click on Settings button under Performance area.
-When you have done then "Performance Options" dialog box will appear with different options. Here select the Visual Effects tab and choose the settings you want to use for the appearance and performance of windows on this computer.
-Turns off all the visual effects in the option of "Adjust for best performance" and when you select the option "Adjust for best appearance" it will gives you opposite effect ,Everything will turns on. Selecting "Let Windows choose what's best for my computer" triggers, as you might guess, different choices on different computers. And to pick and choose individual effects yourself, choose "custom" then decide which ones you want.

Protecting Document with Password

You can protect your document by applying password so that unauthorized person can not display as well as modify your document. You can apply two types of passwords:
Password to open the document:
If it is applied then you have to give the correct password to open the document, otherwise you cannot open the document.
Password to modify the document:
If it is applied then you have to give the correct password to modify the document, otherwise your document is opened but you cannot modify the document. It means that your document becomes read-only.
-To apply a password to document, follow these steps.
* Open Save As dialog box by selecting "Save As" command from File menu.
* Click "Tools" button of Save As dialog box and choose "General Options" from drop down menu, "Save" dialog box appears as shown in figure below.
* Enter first password in "Password to open" text box and second password in "Password to modify" text box (if required) and click "Ok" button of dialog box. Microsoft Word will open "Confirm Password" dialog box for the confirmation of passwords. The maximum length of password is 15 characters.
* Re-enter the password to open and password to modify and click "Ok" button of Confirm Password dialog boxes one by one.
* Click "Save" button of Save As dialog box.

Standard IP Access Control List.

RouterA#configure terminal
RouterA(config)#access-list 1 remark stop all traffic whose source ip 1.1.1.2
RouterA(config)#access-list 1 deny 1.1.1.2 0.0.0.0
RouterA(config)#access-list 1 permit any

RouterA(config)#int s0/0
RouterA(config-if)#ip access-group 1 in

RouterA#show access-lists
Standard IP access list 1
Deny 1.1.1.2
Permit any

Now verify these configuration on router with command us under:
RouterA#show ip int s0/0

Break or recover the router password

-Turn the power switch off and back on to recycle the power.
-Press the Break key or key sequence to put the router into ROM Monitor mode. The break key varies by computer or terminal software. The sequence might be CTRL-D, CTRL-Break or another combination.
-At the > prompt, type 0 to record the current value of the configuration register normally 0x2102, or 0x102.
>o
-Configuration register = 0x2102 at last boot
-Bit# Configuration register option settings:
-15 Diagnostic mode disabled.
-Type o/r 0x2142 to tell the router to boot from flash without loading the configuration in NVRAM at the next reload.
-Type i to have the router reboot. The router ignores the configuration in NVRAM.
-The router runs the setup dialog, Type no or press Ctrl-C to skip the initial setup Dialog.
-Type enable ate the Router> prompt to go to privileged exec mode.
-Copy the startup configuration to the running configuration by using the configure memory or copy startup-config running-config commands. Do not type configure terminal. If you use the configure terminal command, you overwrite the configuration stored in NVRAM.
-View the configuration by typing write terminal or show running-config. View the configured line, vty and enable passwords. Any encrypted passwords need to be changed.
-Enter the configuration mode by typing configure terminal. Change the line of enable passwords as necessary.
-All interfaces are in a shutdown state. Issue the no shutdown command on every interface that is to be used.
-Type config-register 0x2102 to return the router to normal operation at the next reloads.
-Exit configuration mode by pressing Ctrl-Z
-Save your changes by typing write memory or copy running-config startup-config.
-Reload the router and verify the passwords.

Run vs. Save when downloading programe

When you are downloading any program or file from the internet, for example any antivirus program or an email attachment from your friends. Here you will get a dialog box with three options to Run, Save or Cancel. Basically this is confirmation from a user "Do you want to run or save this file", even you can cancel it to abort the downloading.
Here if you select the Run option, only the setup file is downloaded as temp file in your computer temporary internet folder and your computer run this program setup automatically without your confirmation or virus scanning. This is unsafe for your computer if you are downloading this program from any new or unknown source.
But if you select other option Save, You can save this program on your computer in any location. Now you have the full source of program on your computer, you can scan the all program before open it.
Normally you should select the Save option, if you are downloading this program from any free software sites. You have extra security layer if you save the setup file before run it.

Router basic Troubleshooting Tips

Router A# show interface serial0
Serial is up line protocol is up, it is the first message that shows us that your serial port is configure properly. It is just possible when you have already given IP address, run no shutdown and configures some other command.
There are some possible errors messages may occur after the command is given.
Serial is up line protocol is down, it means that check your router encapsulation configuration.
Serial is down, line protocol is down.
You have not given or define clock rate.
Cable not connected or not working.
Serial cable is not plug. Possible causes.
Serial is administratively down line protocol is down.
It means that router is shut down by administrator manually for troubleshooting purpose.

How to set security on your Recycle Bin properties?

This tip is very useful to manage the security of Recycle Bin properties because by default everyone can change the recycle bin sittings using windows default rights. If you want to restrict your users to modify these settings, simply edit the "Permissions for BitBucket" and set the read only rights for all users. Using windows registry editor you can set the Recycle Bin rights for all user.

The best technique to edit the windows registry, always backup the whole windows registry keys on backup drive before editing. Because any mistake in Registry can cause serious problem in your computer to run properly.

Follow the given steps to edit computer registry for Recycle Bin properties:


To enable this feature, you will need to be logged into your computer with administrative rights.


First click on Start button then type Regedit in Run option.


Here locate the location to:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\ Explorer\BitBucket


Here in left side panel, right click on "BitBucket" keys and click on Permissions option.


Now "Permissions for Bitbucket" dialog box will appear to manage the user's rights.


Here select the user name or group "Everyone" from the list under the "Group or user names" category and then allow read only permissions for selected user under the "Permissions for everyone" section.


Now click on Apply button to save these settings and again click on Ok button to finish the process.


Close the registry editor and restart your computer after any changes to go into effect.


To verify these sittings, simply right click on Recycle bin and go to "Properties" dialog box and any changes here will give you a message "You do not have permission to modify the settings for the Recycle Bin".

CONFIGURING STARTUP KEY:

* Go to Start/Run and in the blank field type "syskey" press enter, or OK.

* You should see a small window titled "Securing the Windows XP Account Database". From this Window select the "Update" button to move to the next window.

* The "Startup Key" is the next window. You'll see a couple of options there, but the one we are looking for says "Startup Key on floppy disk", along with some warning about how your system is going to startup now.

* After selecting this click OK, and a pop-up will alert you that the key has been changed. Another message follows asking you to insert a disk in drive A: (Floppy drive).

* Insert the floppy, click OK, and one more window will come up telling you that the Key has been changed and you need to have this floppy disk in order to log into Windows. That's exactly what we want.

When you're all done go ahead and eject the floppy (you might want to slide the little lock up on the floppy to insure you don't format it on accident), and restart the PC. Windows will appear to come up normally, but after it loads the kernel the "Windows XP Startup Key Disk" window pops-up. Grab your Startup Key floppy put it in the floppy drive, and select OK. You'll see Windows load up and bring you to your user logon screen.

I told you this is a cool trick and really helps lock down you PC. I hope you get some use out of this, but please be careful.

Wireless Security

The ability to share an Internet connection is great and the ability to do this wirelessly is even better. Wireless networks are easy to install, you don't have to run cables, and you can roam around a location within the WLAN (wireless local area network), or physical range of wireless connectivity . These features are what makes wireless networks so popular with both end users, and hackers.

The one problem with wireless networks is the vulnerability of your network. A typical hardwired network has physical security due to limited access to the actual network and one opening to the internet (Gateway) has a firewall or two in place (or it had better). This can stop most unauthorized access to your network. The difficulty in setting up wired networks has discouraged a lot of people from installing networks in the first place.

Then a long came the wireless which, as I stated earlier in the article, made the home networking game more appealing and not as intimidating. Having a wireless network means that the physical security that is inevitable in a wired network is simply not there. Anyone in the range of your wireless network can see your network, and if not secured properly, can gain access. If your wireless access point isn't the router on your network then outsiders can slip in behind your firewall. This used to happen at my college, there was an apartment complex behind a portion of the school, and the other techs would piggyback on some guy's network. He had an unsecured wireless network, no one did anything bad to him, they just used him for Internet access but he never knew.

There are some practices you can perform to insure that no one is using your connection or trying to get on your personal network. First and foremost you need to get WEP (Wired Equivalent Protection) in place, which is an encryption that stops unauthorized users from accessing your network. There are at least two encryption types in 802.11b (128bit, and 64bit) and should probably be changed every other week or so. WEP encryption used to be completely the user's responsibility, but now I'm seeing hardware out of the box with at least one encryption key configured, forcing the user to configure his PCs in order to connect.

Using WEP is essential to wireless security, but don't rely on it alone, there are other security measures you can put in place as well. With some wireless units you can set a MAC address filters, witch can really beef up your security. A MAC address is an identification number the manufacturer stamps on a network device, and is (or should be) completely unique. If this security is in place then even if someone knows the WEP Key they still cannot get into the network because your wireless access device will deny it.

There are two other things you might want to do to tighten up your network: The first thing you should do is go through and change all of the default security settings, and passwords. The reason I said this is most Routers and access points usually have a lot of these configuration fields (i.e. username and password or the SSID ) filled out with generic values for ease of setup. The bad thing about this is that people can use these settings against you to gain access into your network. Secondly, with a lot of routers your SSID is set to broadcast by default, this means that it's broadcasting your network's name to the physical reaches of your network. Not good, even if your neighbors don't have the security rights to access your network they will constantly see it every time they boot up one of their wireless PC's.

Creating Charts in Excel.

In excel, you can create chart very easily using the Chart Wizard. The chart created can be inserted into the same worksheet or into different worksheet of same workbook.

To create a new chart, follow these steps.

• Select the data for which you want to create chart. For example to create chart of student marks, the worksheet with data is given below.

Name	Math	Urdu	Total
lilly	25	50	75
Joni	20	55	75
jhon	22	60	82
Eizo	21	45	66

• Click the Chart Wizard button on the Standard Toolbar.

• Select chart type, chart sub-type from dialog box and then click “Next” button, a dialog box is displayed with a sample of chart you have selected.

• Check the Data range and correct it if required and also specify whether you want to plot chart of data series in rows or columns.

• Click ”Next” button of dialog box ,Chart options dialog box appears.

• Specify chart title, X-axis title Y-axis title, legends, Data-labels etc. Click” Next” button.

• Specify chart location in dialog box. The chart can be created in different sheet. By default, the chart is inserted into the same worksheet.

• Click the “Finish” button of chart location dialog box to complete the chart creating process.

How to change the default location of program installation?

You might want to change the location of your system default folder (C:\Program Files) from C drive to another system drives (D or E drive). By default software setup will attempt to install program in C:\Program Files directory. It is good practice to make the backup of the installed programs, if you installed all your programs in other than C drive. If you have little knowledge about editing windows registry then you can configure your computer for this purpose.

Follow the given steps to configure windows registry:

-First click on Start button then type Regedit in Run option.

-Here locate the location to:

-Go to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion

-Here in right side panel, double click on ProgramFileDir and here its default value is

C:\Program Files.

-Now modify the value to any other drive (for example D:\Program Files).

-Now close the registry editor and restart your computer after any changes to go into effect.

Take Bookmarks and Favorites with You

A cool tip to move your favorites list, because there is no any option to copy it. But using a method you can create a printable HTML document.

To create this HTML list, first open Internet Explorer. Here go to File option then you will find here option Import and Export, to run the Import/Export wizard Click here then Next.


Here you can select what to import and export, Select Export Favorites option then click Next button. Next you will get option which folder you want to export. You can select the top folder Favorites or just a specific folder.

Select "Export to a File or Address" option and give it a name and location. Click Next and Finish it. Now you have one html file and you can move it any where with you.

IncrediMail Backup Technique

IncrediMail An alternative e-mail tool with rich formatting capabilities as compare to other tools, usually stores your e-mail under the following folders but we can change location of store e-mail on other drive.

C:\Documents and Settings\User Name\Application Data\IM\Identities\
C:\Documents and Settings\User Name\Local Settings\Application Data\IM\Identities\

These are the default locations for IncrediMail e-mail to back up but best technique is that always use different drive for your important data and different drive for your system file.

How to customize your Browser Toolbars

If you are working with Internet Explorer and want to customize browser toolbars according to your need then open your Internet Explorer. Go to View option then Toolbars, here you can turn off or turn on the many third-party toolbars features, if these features are extra for you or you are using occasionally. In customize option you can change or move the toolbar button, text labels and also icon size. You can restore these changes again with the same procedures.

How to back up your Messenger Yahoo!, MSN, ICQ.

MSN, Yahoo and other messenger that you can use to send message to other people who are online. Your message delivered immediately to other person, when other give you response then it is just as in a face-to-face conversation. With the help of messenger you can do much more than send text messages to other people. You can send audio and video files and conversations, place a phone call from your computer all over the world, hold an online meeting, play games, share programs that are installed on your computer, and more.

But interesting thing is that you can backup copy of your text message, audio, video conversation and your messenger's contact list, to be able to recover your contacts after a computer crash, a virus or system re-installation. Backing up your messenger data can be quite a challenging task. But the important thing to remember when you install your messengers is that always install it on other drive than system drive like on D:\ or E:\ drive, because most messengers usually keep its data either under the folder they are installed in or under one of the user profile folder subfolders. Typically, your computer will offer you path like this.


-C:\Program Files\


-C:\Documents and Settings\User Name\

-But you change your messengers installation pate like

D:\messenger\...

Move the Location of your Temporary Internet files.

When you are browsing your internet, the website you visit placed some temporary files on your computer. The main purpose of temporary files to save your preferences that you specify for future reference. Normally internet temporary files are saved on C drive in windows folder but you can change the location of temporary folder to hide your internet browsing history from others.

If you are using Internet Explorer then follow the given steps to change the location of temporary folder.



- Open Internet Explorer, click on the Tools then Internet Options.


-Go to General tab then Settings button under the Temporary Internet Files.


-Here click on Move folder button then select new location to save Temporary files on different drive or computer.


-Now restart your computer for this change

How to backup of your computer installed drivers?

You can easily create the backup of your computer installed drivers (just the particular or all drivers) and use it to troubleshoot any driver problems. This backup will be very useful when you will format your computer window due to any reason. There is no need to search the drivers from internet or drivers CD, just import the driver backup and within five minute, you will complete the driver installation process. You can move this backup from one computer to other computer for installation.


-To complete the all process, we will use a simple tool called DriverMax. Using this tool, we can easily export the backup of any specific or all drivers and then import it for reinstallation later or elsewhere. You can free download (with free registration code) this tool for windows XP and Vista also. Download it and run the easy setup.


-After Installation launch DriverMax, the first screen you will get with title "DriverMax - Version" and options "Export drivers, Import drivers and Installed drivers report". Just click on "Export Driver" option to start backup process.


-Now after welcome screen, system will take few seconds to create the list of all installed drivers and then show you all installed drivers list.


-Here you can select any specific device driver or click on "Select all" button to create the backup of entire installed drivers.


-Press the Next button and in next screen you can select the export type (simple backup or in zip format) and then choose the backup location (always choose drive other than C drive).


-Again press the Next and system will take some time (depend upon the size of your drivers) to finish exporting the selected drivers.


-Click the "Open extraction folder button" to view the backup files or press Close button to finish it.


-Now you can use this backup files (using import option) to restore drivers backup or move to any other computer. Copy the Following link to download it.

Searching Information tips using Search Engine

If you want to get some information about any topic using search engine, the search engine will search the given information and will provide a list of links of websites along brief description about each website. You should use the right search terms for relevant results. The following points must be noted to search the information on the internet.
-You can type all word in lowercase and also in uppercase, search engine will return the same result। But the best practice is type search keywords always in lowercase.
-Use + sign between words if you want to search the all words. For example, to search history of Football in Europe, type as: history+Football+Europe

-To search the exact match, write the words in double quotation marks. For example to search the map of Europe, then type as: "Map of Europe"

- Always avoid to use "and", "or" with search keywords, because these words will affect the search result।

Set Explorer Multiple Homepages

Many web browsers like Mozilla Firefox but now Internet Explorer 7.0 also allow you to set the multiple home pages. You can open all home pages at the same time; this is great option to open your favorite websites with a single click. But you have option to set single home page according to your need.

Follow the given steps to set multiple home pages in Internet Explorer.



- First open the Internet Explorer 7 and go to the option Tools then click on Internet Options.


- Select the General tab, here you will get option "To create home page tabs, type each address on its own line" and type the URL in the Home page section.


-Type one URL in one line then press Enter to type another URL. Press Ok to finish.

Take action to stop the Viruses

Computer virus program negatively affects the working of a computer by altering user data or information without the permission or knowledge of its actual user. But you can prevent your computer data and resources from viruses, if you follow the given tips and tricks.



-Never open unknown e-mail messages, and always scan first all email before downloading even if you know the sender of the message.


-You should minimize the data transfer between computers through use of USB drives and MP3 player, if it is necessary then always scan first before open it.


-While using the Internet, avoid downloading free ware software without first checking it for virus. Normally the key generator sites are the main source of virus.


-Always use antivirus program with latest version, to detect and remove viruses from your system. You should update antivirus program periodically, because older versions of antivirus may not remove the new viruses.


-Always keep backup your important data, because your can restore your data using backup if a virus deletes your data or modifies it.

Hangs up internet dial-up connection

When you are browsing your favorite websites using dial-up internet connection, your incoming calls can create problem with your modem if the call waiting option in your modem sittings is enable. Your modem may be hangs up and disconnects the internet connection frequently. Normally when you disabled the call waiting option in your modem sitting and any body tries to call you, he will get the busy beep during internet connected. You should always disable the call waiting option to avoid modem disconnectivity or hangs up.

-To disable the call waiting option, first click on Start button, then Network Connections.
-Here double click on your internet connection and click on Properties button then General।
- Under General tab select Use Dialing Rules box then click on dialing rules button.
-Here select My Location then click on Edit button. Under General tab select the option To disable call waiting dial and put any number in next box like
-At the end click on Ok button and dial your connection again.

Check program before downloading

Computer security can be defined as the protection of computer and its data from any loss or illegal access from other users. Normally file virus or program virus attaches itself with program files and activates when these program files are run. Infected program files are normally downloaded from Internet. When ever you are trying to download any program from the Internet, always download from trusty sites. On Internet the Software cracker or key generator sites are the main sources of computer virus.

When you are downloading any program or file from the internet, for example any antivirus program or an email attachment from your friends. You must select the Save option, if you are downloading this program from any unknown or free software sites. First scan the downloaded program before open it. You have extra security layer if you save the setup file before run it.

Different File Type from Storage point of view

File organization is a technique for storing and arranging data on secondary storage devices so that it can be retrieved easily when needed. It includes the physical order and layout of records on secondary storage devices. The techniques used to write and retrieve data to and from the storage devices called it access methods.
There are main three type of files from storage point of view.

-Sequential files
-Direct or random files
-Indexed sequential file
-Sequential Files
In sequential data files, records are stored on the storage media in a sequence. No locations are specified for individual records. The records are stored in an order, one after the other. Similarly, records are also retrieved in sequential order. It means that records are accessed one after the other in the same sequence in which they are stored on the storages devices. For example, to access a particular record from a data file, all records are searched one by one until the specified record in found. Therefore, accessing records in sequential files is very slow.
-Direct or Random files
Direct files are also referred to as random files. In these files, records are not stored in a sequence. Each record is stored by specifying a particular address or location within a file. The address is calculated against the value of the key field of the record. Sometimes, the same address is calculated, which creates a problem to store record. This problem is known as synonym. Data accessing from direct files is very fast. A record is accessed directly by specifying its address.
-Indexed Sequential Files
These files can be processed sequentially as well as randomly. In these files, the location of individual record is also stored along with data of record. For this purpose, an index is created to keep the track of locations of individual records.
Index refers to the location on the storage media where record is stored. You can say that an index is just like a table that is used to find out the location of a particular record. The key fields of the records are stored separately into the index along with the address of each record. Usually, an index is created in a new file called index file. The index file is updated whenever a new record is added or an existing record is deleted. Indexed file organization is more effective and fast in accessing data from data file than sequential file organization. These files occupy more space on the storage media but accessing speed of records is same as random access files.

Scan Individual Files for Viruses

We often recommend that when you download files you should scan for viruses. The same is true for attachments sent via email (although, if you have decent antivirus software this should be taken care of).
But do you need to scan your whole computer? No, you can scan just one file with most AV software (Norton, McAfee, AVG).
-Just right click the setup file and you should see "Scan with whatever AntiVirus" or just "Scan for Viruses".
-Your AV software will come up, scan the file, and let you know of any infections.
-Some newer AV also lets you scan zipped folders before unzipping.
-Knowing that it's safe, you can then proceed with installation of the program or opening the file.

Web Bugs

Have you ever heard the term Web Bug? How about Web Beacon or Clear GIF? Well, don't feel left out if you haven't, it's not everyday terminology. The terms I mentioned are different names for the same thing. For the sake of remaining simple I'll stick with one name Web Bug. So what are Web Bugs and what to they do? They are small (1 by 1 pixel), usually transparent gifs hidden on websites or e-mails within other images like banner adds. Web bugs come from a different site than the one you are viewing but are most often affiliated with the site being viewed.
They are a lot like cookies in that they allow sites to recognize you and track where you've been. Web Bugs have a couple of major differences however. Web bugs share your information with any site that you may visit with the same type of web bug imbedded on it. The personal information bugs are sharing can be harmless information or very personal information, it depends on what information you have put on one of these sites. If you have given one of these sites information like your email address, then every other site you visit with the same bug will have your email address and can now send you spam. By sharing this personal information between sites these entities using bugs can get your email address and send out more spam and web bugs right to your front door. If you visit a site that recognizes you from a Web Bug then that server can not only track you but also send images and blocks of text to you. Web Bugs are also harder to detect than cookies because they are hidden, extremely small, and invisible.
These Web Bugs can also be placed in e-mails, a favorite trick of spammers is to hide a Web Bug in a random email. Opening or even previewing this e-mail can initiate the Web Bug process, which tells spammers that this is a valid e-mail address when someone views it. This validates your address, essentially making you part of their list of e-mails to spam. Most of the more recognized e-mail clients are affected by this such as Outlook Express, Gecko for Linux, Netscape, AOL, and more.
So, how do you stop or prevent these web Bugs from tracking you? As far as e-mail, make sure you don't open or even preview e-mails from unknown sources. Another thing you can do to prevent the Web bugs from biting is to block images in your e-mail all together, this will stop the GIFs from getting through your defenses. Win XP Service Pack 2 turns this setting ON by default in Outlook Express, and other e-mail clients have similar options (i.e. MSN/Hotmail and AOL).
You can also configure tougher cookie settings in your browser, but keep in mind all of these settings will affect the way you surf the web and view your e-mail. You can get advertising blocking software, but these programs have a hard time distinguishing between images that show information and images that are crawling' with Bugs. You can also go through the HTML code and look for the img tag that relates to a cookie (sounds like fun).
So are these bugs really something to get all worked up about? Well if you really don't like the thought of constantly being tracked and evaluated. If you don't like spam or pop-ups then this could be something you might want to at least regulate. You can figure out exactly what a web bug is doing by viewing the privacy policy which should be located on the website of the owner of the bug. If you don't find the privacy policy, you can always send the company e-mail and ask for what purposes do they have web bugs on their site.