I would first say that it is probably overheating somewhere...that is the most common reason for the problem you are facing... Do you have plenty of fans? And, as you are running you computer, feel for hot spots like the RAM, your video card, the Mobo around your processor, you hard drive...
He is? wOOt me has been demoted! Oh I thought u meant noob hehehe! Heat bad caleb and electronics bring in bad bad dust even in a perfectly clean home! Air from you or a shop compressor add moisture meaning never do that! Lack of cool would be my first clue to shut down.