From the Microsoft.com website, with Windows Installer CleanUp Utility,
you can remove a program’s Windows Installer configuration information. You may want to remove the Windows Installer configuration information for your program if you experience installation (Setup) problems. For example, you may have to remove a program’s Windows Installer configuration information if you have installation problems when you try to add (or remove) a component of your program that was not included when you first installed your program.
I downloaded it and tried it. I was able to remove some leftovers from an uninstalled copy of Microsoft Visual Studio .NET 2003. I was not able to remove a copy of LogMeIn that did not install properly.
It appears that the utility can run on most 32 bit versions of Windows from 95 through Vista and on the 64 bit versions of Windows XP through Vista.
Not for everyday use, but great when you need it.