Whenever I play games (ex. Warcraft III, Rise of Nations, Diablo II), my sound keeps shutting down at random times. When I want my sound to return back to normal, I have to restart the computer. I just bought a new PC a few days ago, and this started happening. On my very old PC, this problem never happened.

Does anyone here know what the problem is?

I went to dixdiag and checked the sound part, it says the name is Realtek AC97 Audio.