Originally Posted by winterfreshpwnz
Reformat your hdd.
Pay no mind to that answer. Please.
Formatting the drive is not the cure to the problem.
Most likely it's a driver problem as stated by GreySteelFox. This is the place to start looking for an answer. If the system still insists on being unstable then look to a hardware incompatability problem as the next step. And finally look at your power supply. Some times it's as simple as when you tax the system the PSU is just not up to the job and faulters.
Got any more questions just come on back. We'll be here...