Hi everyone

iv just bought a Gigabyte EP45-UD3L and iv everything works good accept for games and prety much anything that needs the graphics card to run. My card is an Asus ENGTX 260, whenever i go into a game the pc just reboots no errors nothing. at first i thought my card was broken but it put in another one and it works just fine. So then i put my old mobo back in which is also Asus and everything works fine. Im thinking that it could the drives for the card, maybe they arent compatible with the gigabyte mobo drives?
Any help would be great this is really killing me trying to solve