EAH 4850 Bluescreen on videogames

Hey there, I'm new to the forum but here goes nothing:

Recently, my computer has been blue screening on any videogame I try to play. I've tried multiple ones, and every time as soon as I go into the actual game, it blue screens. I could sit on my desktop all day, doing anything I want and nothing will happen. Only once i try to play anykind of a game will my computer restart.

I've had this computer for a little over a year, built it myself.

Motherboard: ASUS M3N78 Pro
Graphics Card: ASUS EAH4850
Processor: AMD Athlon 64 Dual Core 5600+, 3.0 GHz
Power Supply is 650W

I've updated all my drivers, to try to see if that's the cause of this, but no such luck. I can't imagine it'd be anything other than the graphics card, but I can't really back up my reasoning either.

Any help will be appreciated.

Remove your graphics card and use your onboard graphics start window and uninstall EAH 4850 driver install onboard graphics driver and start with any game if that works then problem may be with your graphics card go and replace it if under warranty else check for ram and motherboard.