G400 crashes out to desktop

[Mark T]

I have recently installed a G400, I now have a problem where when Playing Rogue spear (rainbow 6 II)and another game after a very short while the game crashed out to the desktop, I have the latest driver and the AGP apature has been changed to 256 but the problem still occurs.

My spec is
AMD Athlon 550, 256mb ram, Asus K7M motherboard.