HELP!!

[kemo646]

Well, I just built my new computer, and it was running everything fine.....I installed the couple games it came with..and those worked....but any other game I tried installing wouldn't....like Doom3...or Battle for Middle Earth.....My computer would just lock up at the beginning screen. Its only doing it with the games I didnt get with the video card from gigabyte...its an X800 Pro...Im pretty sure I got the right most updated drivers too...this sucks...brand new computer and I cant even run the games....Only the ones that came with it. I would greatly appreciate some help.