If you’ve installed a program on Win 7 and was unable to uninstall it the usual way, i.e using Add/Remove Program in the Control Panel, then you should try Windows Installer Cleanup Utility….
You can download it here. Once downloaded, you need to run the installer file as Administrator!
Then go to Program Files-Windows Installer Cleanup and locate the file msicuu.exe. Right click that file and under Compatibility tab, set it to run as Vista compatiblity and as Administrator!
Do the same for msizap.exe! Once you have set the compatibility settings for both files, you can now run msicuu.exe and choose the program that you fail to uninstall normally and click Remove.
Source: Windows 7 Forum