Overheating was the main issue at that point, I believe. I would put a huge-*** fan in front of the computer and it would work fine. Since then, I've done a massive overhaul of the computer. New case, upgraded to a Quad-core processor with a Zalman heatsink due to paranoia. The only parts I've kept are the RAM, hard drives, and graphics card. I did a complete re-install of Windows XP. The new processor runs nice and cool.
Thing is, I'm having the same issues that I had previously.
I have an ATI Radeon 1900XTX graphics card, which should be more than capable of running a large spectrum of games at max with no issues whatsoever. In fact, it used to do so, back when it was new. Now it can't even run WoW without turning everything down to an absolutely pitiful level. I'll get the graphics glitchiness that's referenced above, and after a few minutes it will lock up completely, and I have to restart.
This is getting ridiculous. I suspect that the graphics card is having heating issues, but I don't know how to confirm this.
Any advice?
EDIT: Redundant title redundantly brought to you redundantly by the Department of Redundancy Department.
Edited, Apr 28th 2008 7:21pm by DodoBird