Well my brother 4850 giving problems. tried to install catalyst 10.4 and then is when the horror started. After restart the card would show bios post. xp loading screen then when it starts xp the there is no display. you hearing all the windows loading sounds but no display. so i revert back to board igb and everything show fine. so I do a driver clean. after driver clean reboot again. same problem. so i did driver clean again. same problem been trying every which way with old catalyst version to install but when i am on igb the catalyst driver not seeing t the 4850 but it does do the bios post and xp loading screen but no xp itself. so i think it must be hd issue now. so before i go put on clean copy of xp any other suggestion s?