Happened once on Enterprise and another time in Home premium, both msdn official versions.
The first time i didnt realize which was the cause but now i'm pretty sure it's it. The changes were apparently harmless so I didnt make a backup. FIY system restore does NOT fix this, so maybe there is more than just the registry cleaner.
Not possible to access it in computer management or event viewer.
The service is shut down and it cant be restarted. What's more odd is that a system restore does NOT fix it (i.e a total reinstall of the OS is needed, i had to do that 3 times on my new computer, once trying to install a bugged driver, but that's another matter).