Strange and sudden video problems

So, I install Black and White 2. It locks up maybe 20 minutes into the game. I try and run City of Heroes. It locks up as soon as I get into character selection. Both of these crashes were pretty bad, with the sound skipping and what have you, forcing me to just turn the computer off and on again.

I put City of Heroes into Safe Mode so it'll reset my graphic settings to the minimum, then put it back into normal mode. I readjust the graphics settings one a time to my old settings, and as soon as I enable shadows, and return to the game, the game crashes.

Keeping in mind I'm not incredibly computer smart...what the hell is going on here?

Direct x maybe

I tried DirectX diagnostics and had no problems, and tried to reinstall DirectX 9.0c. The problem persisted.

Try updated video drivers, Omega drivers, etc.