Removal tools and uninstallation instructions for various antivirus software

Currently am using Avast AV and for some reason ,want to change my antivirus software,and suddenly encounter problems while uninstalling my old antivirus.Then what will be the solution to this of course without formatting my windows.Many antivirus software producers offer special tools or instructions (so does Avast).Neat and thorough uninstallation of a program,is a must as it will be less problematic .

Please note that some of the advice and tools that are linked to from here may be unofficial or from secondary sources. In case of doubt, kindly ask the producer of your previously used software whether there is a recommended removal tool, and, as a precaution, backup your system before applying any tools.

Credit: Avira Support Forum

The list starts here.

Avast
http://www.avast.com/eng/avast-uninstall-utility.html

AVG
http://www.avg.com/uk.download-tools

Avira AntiVir
http://www.avira.de/en/support/kbdetails.php?id=135

BitDefender
"Normal" versions:
http://kb.bitdefender.com/KB333-en--How-…itDefender.html

Server, "Enterprise Manager":
http://kb.bitdefender.com/KB403-en--How-…ws-Servers.html
http://kb.bitdefender.com/KB371-en--How-…anager-2.6.html

Bullguard
Bullguard 8.5: http://www.bullguard.com/support/product…/uninstall.aspx
Bullguard 8.5 Vista: http://www.bullguard.com/support/product…tall/vista.aspx
Bullguard 4.x: http://www.bullguard.com/support/product…install/4x.aspx

eTrust
http://supportconnect.ca.com/sc/kb/techd…creen=kbresults
http://answers.google.com/answers/threadview/id/756917.html
http://forums.techguy.org/malware-remova…-etrust-av.html

F-Secure
http://support.f-secure.com/enu/corporat…/removeav.shtml
http://www.f-secure.com/de_DE/support/kn…ls.html?id=2109
http://www.f-secure.com/de_DE/support/kn…ls.html?id=6640

GDATA
http://www.gdata-software.com/support/downloads/tools.html

Kaspersky
http://forum.kaspersky.com/index.php?s=9…showtopic=67812
http://support.kaspersky.com/faq/?qid=208279463