Removing stubborn uninstall programs

1. If there's been any manual hacking of files and/or registry, use System Restore to get things back to how they were before it started.
2. Download safemsi.exe from here. The utility lets Windows Installer be invoked in Safe Mode.
3. It might be necessary to start the Operating System in Safe mode.
   Boot into Safe Mode by pressing F8 before the Vista, Windows XP, Windows Server 2003 boot screen starts.
4. Run safemsi.exe.
5. Remove the offending application as normal using Control Panel.

Link: http://www.jsifaq.com/SF/Tips/Tip.aspx?id=9233