I've railed against Microsoft before for how they seem to specialize in anti-discoverability of features in their programs. This also applies to utilities that come with the operating system. There's a nifty little tool called System File Checker. SFC is designed to scan your system files and replace any incorrect versions. Doesn't this sound like either something you should know about or something that should run automatically? Isn't this just as important as system updates? Why would I want to keep around incorrect versions? Couldn't it at least run automatically in VerifyOnly mode? I was having an issue where the Windows Desktop Manager kept quitting on me. This would hang up my mouse keyboard and monitor for over a minute. It would only happen a couple of times a day but it was still a nuisance.
I lived with it for it for quite a while before I discovered sfc. I ran sfc from a command prompt. Under Vista and Windows 7 you want to right-click on your Command Prompt shortcut and select Run as Administrator.
Just typing sfc in the command prompt will give you some information on the various options for the tool. Pick your poison and let loose the dogs of cleanup. This solved most of my desktop manager issues, since it identified some files that needed to be updated. Now the desktop manager only goes on strike about once a week or so.