Halflife Episode 1 crash in Boot camp

[BrenMyster]

I have installed half-life episode 1 on my boot camp partition but it keep on crashing in game, usually about 5 min in to the game when graphics get intense, when i lower the graphics setting the crash time does get longer but it still happens eventually

I have downloaded the new x1600 drivers but it wont let me install since it says i don't have a x1600, which i obviously do in my imac.

Anyone have this same problem?

Anyone have any suggestions?

Thanks