Windows Live Messenger Uninstaller is a small tool that basically removes a broken Windows Live Messenger installation. It really uses only the windows installer (msiexec.exe) to do the job combined with the CLSID of the installation that uniquely identifies the WLM version.

The symptoms might be that when you want to reinstall the application it might say that it is already installed, while actually it is not. When trying to remove it with the usual Configuration – Add/Remove software steps, it might not even appear in the list, while the setup of the WLM says it is really installed.