Another tool that I have known about for some time but figured I should write about before I forget: The Windows Installer CleanUp Utility. Its a great little tool that will give you a list of all the programs installed on your machine and allow you to rip out their registry keys. Great for stingy antivirus or office installations that just don't want to uninstall. Run this tool, remove it, and reinstall on top of it... then uninstall it for reall. Voila!