Windows Crashing While Running Games

I've searched the forums high and low and still have not found the answer to my problem. I'm currently running Windows XP Professional SP2 Via bootcamp on my macbook pro 15 inch 2.4 ghz computer...only when i run games (Counter-Strike 1.6 & Team Fortress 2) windows seems to crash randomly. ive tried reformatting my entire computer and reinstalled windows xp..still no luck..what could be the problem with this? a game like counter-strike 1.6 is pretty much out of date and the engine is pretty simple..so i dont understand why it would crash? .. please someone help me out..i would greatly appreciate it..because im ready to shell out money for a new PC so that i can play my games.. 😟 😟 😟