Many times, the Windows Control Panel, Uninstall Programs applet proves insufficient for un-installing AntiVirus or Security Suite installations, as a result of which they leave unwanted remnants on your PC. This often then causes problems esp when you go on to install another security program. It’s thus always advisable to use the AntiVirus Removal Tools or AntiVirus Uninstallers for completely removing anti-virus software.
AntiVirus Removal Tools
Here is a list of for leading antivirus and security software for Windows.
Avast: Use their uninstallation utility AvastClear.
Avira: Avira AntiVir Registry Cleaner Tool will help you clean up all the registry entries left by this anti-virus software after the uninstallation.
BullGuard: Uninstall BG.
Dr. Web: Removal Tool.
eScan: esRemove Tool.
F-Secure: Un-installation support and tool.
F-Prot: FPavex Tool.
G DATA: Download and use the G Data removal tool AVKCleaner. See under the Tools tab here.
Kaspersky: They offer a free utility that helps you to completely remove all Kaspersky Labs products. Download Kaspersky Products Remover.
K7 Security: K7 Removal Tool.
McAfee: The McAfee Consumer Product Removal tool (MCPR.exe) removes all 2005, 2006, 2007, 2008, 2009, etc., versions of McAfee products. Use it to completely uninstall McAfee Internet Security. This option should be used, only after you remove your McAfee product through Uninstall Programs.
Malwarebytes: MBAM Cleaner.
Microsoft Security Essentials: This Fix It helps you uninstall Microsoft Security Essentials
Panda: Panda Uninstaller.
Quick Heal: Uninstaller.
Symantec (Norton): Use Norton Removal Tool.
ThreatFrire PC Tools: Remove ThreatFire.
Vipre AntiVirus: VP Cleaner.
Webroot: CleanWDF Tool.
ZoneAlarm: ZoneAlarm Uninstallers.
If I am missing something, please add a comment below.