Quote Originally Posted by 'Aarelan',index.php?page=Thread&postID=217092#post 217092
Might be an over temp alarm.

If so, the reason it happens when you box is because it's probably the only time you hit the CPU that hard.

Are the fans and stuff all turning as they should?
Now that you mention it I do tend to have no mercy and burn my PC on multiboxing for 16+ hours everyday. I only leave it turned off once I go to sleep.