WoW:System CrashesFollow

This is a copy of a thread that I posted in the official tech support forum. I figure I should cast my net far and wide, so I'm posting it here as well.

I had been running WoW with no problems for a few months when WoW began to crash after I restarted my computer a few days ago. My screen would either go entirely black or freeze displaying the image on the screen, and sound would either skip or continue playing. I have tried to fix this problem by doing the following:
-Restarting computer
-Using system restore to a few days before the problem started
-Running chkdsk /f
-Defragging
-Uninstalling and reinstalling WoW
-Reformatting my C drive and reinstalling Windows
-Reinstalling WoW to a different drive
-Running the repair program (I got an error telling me that there were too many errors to fix and that I needed to reinstall. As I got this error directly after reinstalling WoW, I'm at a bit of a loss. I have not tried running the program since updating WoW, I will try this as soon as I return home).

I will post a Dxdiag as soon as I am back home

What I find most strange about this problem is that it kind of came out of the blue after a simple restart. As far as I know, I hadn't installed any new software or hardware. Even if I had, a complete wipe and reinstall of Windows would have fixed it. The problem is not with my copy of WoW, as I've installed it on a separate computer and it runs with no problems. The only explanation I can come up with is that I have some kind of hardware problem, but I don't understand why it would start after I've been running the game for several months already. I had restarted the computer several times before with no problem.

Any advice is greatly appreciated. Thanks in advance.