Battlefield Bad Company 2 crash?

I started up Battlefield Bad Company 2 on my PC and the first level worked fine, but at the part with the loud EMP, the sound started turning off and on, and the game was basically stuck on the 2nd level loading screen, and the sound was still turning off and on. I'm pretty sure it's not my PC, because Modern Warfare 2 worked really well on it. How can I fix the game?