Amd driver update issues

I have two AMD 6850 graphics cards in CrossfireX and every time I try to update the drivers it fails. After my computer restarts it comes back on running the intel onboard graphics and device manager states that my video cards aren't working properly and I have to roll back the drivers to get them to function. I've just been using AMD's auto-update utility since I don't have that much knowledge about software in computers, but I do play a lot of games and I have to imagine updating my drivers would fix some issues with them and improve frame rate.