[Betty_Swallocks]

Originally Posted by revol68

awful AI, repetitive action. It might have cut the mustard back in 2001 but for a 2007 release it was a very poor showing.

That's your opinion, but it's not very helpful to the op now is it?

My feeling is that it's probably hardware or more likely driver related. Try updating your sound and graphics drivers.
Oh, and reseat everything on the motherboard that can be reseated.

Failing that, format and reinstall rarely fails to cure niggling software issues. A sledgehammer to crack a nut perhaps, but in my experience it's often quicker to wipe your hard disk and reinstall everything than it is to faff about, sometimes for days as in your case, trying to isolate the reaql cause.
TBH when something like that happens to my PC I don't care what causes it. I just want it gone.