Computer Freezes to Grey Screen

File: t1larg.laptop.light.ts.jpg (21KB, 640x360px) Image search: [Google]

21KB, 640x360px

So my computer is acting strange. If I am on it and not using it in a resource intensive way, like if I'm just browsing the internet, it will freeze to a grey screen and will no longer respond, forcing me to shut down my computer. The only way to prevent this so far seems to be by running a game in the background, like WoW.

Any idea what the cause might be? I'm thinking it might be some weird kind of power saving where a part might shut off if it's not being used much, but I honestly don't know. It sounds like the opposite of what I'd expect to happen, which is a computer shutting down when using it too much, not too little.