Oh dear, ... doesn`t exactly inspire a whole lot of confidence, does it?
I`ve been reading some of the stuff in the MSDN Developers` centers click here ... heavy going, a lot of it, but it`s perhaps not surprising that much of what is being done is to improve on what has gone before ... which doesn`t say much for what has gone before, I think.
What have you been advised to do this time? File integrity verification tools? Hotfixes? Registry editing? Uninstall/re-install?