You need to provide us with a bit more info than that please. How long does it take the blue screen to happen? Is it fairly random or does it seem to always happen around the same point. Like 15 or 20 minutes into playing (consistent, would point to a heat issue) or is it random (like one time it happens in 5 minutes and the other it will happen after an hour, would point to a memory issue.)
Or, does it blue screen as it is trying to boot into Windows? if that is the case, it would point to either a memory issue again, or you had some other sort of hardware failure which I would guess would be a video hardware failure.
Please provide us with as much info as possible. Remember, with computer issues - especially ones like this - there is no such thing as too much information.