what u have is called a conflict. Either ur temps are high, there is some confusion with the bios and your IRQ settings or other things. I had the same problem when i first got my computer. when playing games the temps would shoot up to 59 degrees and would freeze after 45 minutes. U can try taking off the side panel, adding fans, replacing your thermal pad or buying a new heatsink for your CPU. I did 3 of those and i never had problems again. For more on CPU cooling be sure to read the wealth of information on the site as well as the cooling forum.