Windows Installer Cleanup Utility (MSICUU2.exe) has been an invaluable tool for fixing Windows Installer related issues but sadly Microsoft has decided to discontinue it citing the following :
While the Windows Installer Cleanup utility resolved some installation problems, it sometimes damaged other components installed on the computer. Because of this, the tool has been removed from the Microsoft Download Center. The Fix it Solutions in this article provide the ability to fully remove Office 2003, 2007 and 2010 suites without damaging other Windows components.
If you are still looking for Windows Installer Cleanup Utility we have direct-download link available at the end of the post.