I am going to make a guess and say that you are having some heating issues to check this install HWMonitor from http://www.cpuid.com/softwares/hwmonitor.html
and then run it up and watch to see if the temps on the processor and the video card. If it is the processor check to make sure that the HSF is properly attached to the board and is clean. If this doesn’t change look at picking up a 3rd party HSF.
Intel Enthusiast Team