Blue screen playing games

am having a problem and I am hoping for some advice. My computer runs
fine except when I try to play games and after about 10min of game playing I
get the blue screen of death. It says about disabling system bios and
caching which are already disabled, any way the last thing it says is :

Technical information:
STOP: 0x0000007F (0x00000008, 0x80042000, 0x00000000, 0x00000000)

I'm starting to think that my video card may be stuffed, cause I have tried
reloading drivers, directx and the problem still persists, so if anyone has
any ideas what may be wrong I am open to suggestions.

My specs:
Amd Athlon Xp 3000+
1 GiG DDR 400 Ram
Geforce Ti4200
2 X WD 80G Harddrives
7VT600 Gigabyte mainboard
Windows Xp Professional.