!!big Problem!!

Hi, I have a pretty big problem that has been pissing me off, first my specs.

specs:
XP Pro
1.3 GHz AMD Duron
Radeon 9250se 128mb ddr
384 mb ddr ram
SiS 7018 audio driver
ECS EliteGroup K7SEM mobo
Maxtor 6E040L0 38.2 GB harddrive
LG Studioworks 700S monitor

Whenever I play World of Warcraft, when I get to a very crowded part in the game, my computer locks up and makes a humming sound out of the speakers, and other times it doesn't lock up, it reset's, my monitor and minimizes the game and an error saying this pops up "VPU recover has reset your graphics accelerator as it was no longer responding to graphics driver commands", What is the problem!? Could it be my monitor and vid card conflicting?? Ram problem?? what! I updated my vid card drivers and still :/

 

your vid card took a nose dive