BleepingComputer.com: Screwed Up Graphics

Alright, I've been having this problem for quite a while now, but it's either getting worse or just annoying me more. When I play games (not flash games, installed ones on my computer), they start to "stretch" or distort on the screen. It happens in almost every game I play, to varying degrees and few exceptions.

It generally looks like these, sometimes with more color distortions.





Games it affects me most in:
Oblivion
Portal
Homeworld II
Age of Empires III
Sins of a Solar Empire
... that sort of thing.

The odd thing is, some games don't show any symptoms like it. For example, Civilization IV:Warlords, or Stranded II are very rarely/never affected.

Occasionally, after I close out of the game (usually having to kill the process) my desktop starts to freak out as well, with my screen flashing black every few seconds. When that happens, I have to restart before I can do anything else.


Like I said, this has been happening to various degrees since I got my computer (a year and a half, maybe). I've had a suspicion that it's a DirectX issue, but I've tried to reinstall before, with no luck. Of course, it could just have been that I wasn't doing it correctly. I dunno.

I don't think it's my video card because some games play just fine, while others are marred by the problem constantly. I've tried playing the games in all sorts of resolutions, and (while it may change it back to normal for a few seconds) it never does any permanent help.

Please help, good community of BleepingComputer. I would forever be in your debt (and by that I mean a quick thank-you before I start actually enjoying my games.