High Quality Content by WIKIPEDIA articles! The Windows Installer CleanUp Utility (MSICUU2.exe) was a software utility for the Microsoft Windows operating system designed to solve uninstallation problems of programs that use the Windows Installer technology. It looks up registry references and files related to Windows Installer that were installed by various programs, and forcibly wipes invalid entries out. It works in all 32-bit and 64-bit versions of Microsoft Windows.