Many security applications leave behind files and registry entries making it difficult to install a different or new application of your choice. In such cases AppRemover can help you out.
AppRemover is a tiny, stand-alone program which can remove all kinds of antivirus, antispyware and broken security applications from your computer.
It ensures that there are no remnants of old and outdated security software lurking on your PC by removing their registry keys, folders and files.
Some security tools may require an administrative or account password before uninstaller can start. AppRemover can uninstall even those tools, regardless of whether or not you know the password. And being a portable app it can be easily carried around on a Flash drive and run anywhere without installing.
AppRemover supports antivirus software such as McAfee, Norton, Avira, F-Secure and TrendMicro as well as antispyware tools such as Ad-Aware and SpywareBlaster. Full list of supported applications can be seen here.
AppRemover is free, and works on Windows 2000, 2003, XP, Vista, 2008 and Windows 7.