Irregular Windows Freezing Issues

I'm not quite sure what the root of the problem is, however, my computer is freezing at almost random points. Usually, I noticed that sometimes it will freeze if I'm just playing music or browsing the web. However, the more strain I put on the resources of my computer (i.e.:Running games) the faster it locks up.

I can no longer run any game for longer than 10 minutes without it locking up. Not even flash games.

So, /comp/, is this an overheating issue? Or is this a pin-connection issue? Or is it a software issue with my copy of Windoze?

Thanks

Well, I got a little fan and opened up the case to let it cool it off.

I'll report back again if it freezes, if it doesn't it was definitely overheating, if it does, it's definitely the power supply.

Of course, more differential diagnosis is always helpful.