My computer is a pentium 4 2.8 gig with an ati radeon 9800 atlantis. The mobo is an ASUS P4PE-X. Here's the problem: I will start playing a game and everything will be running fine for a few minutes and then the computer will emit a series of beeps that sound like a warning. The computer will then shut itself off unless I exit the game. If I exit the game, the beeps stop and the computer runs as if nothing happened. The beeping only occurs when I play games. I thought it might be over-heating but my diagnostic tools showed that the CPU never went above 111 F. Please help as I greatly wish to return to playing Half-Life 2. Thanks.