Video card probs

Alright...some of the games i have been playing started to lag a bit, so i tried to update my driver (ATI Mobility 9000) from ATI's website. Upon install, i got an INF not found error. Thinking it could have been a direct x problem or something i checked DXdiag. While it was loading I got a memory dump...problem was atiduag.dll. I found a good driver from support.dell.com and installed that, thinking it fixed my atiduag problem, i tried to run bloodrayne and i got the same memory dump. Anyone got any ideas. I unistalled the driver before i tried the ATI's site driver for the second time. I dont know if i did it right. So i guess help me to unistall it right, and two, any ideas about this atiduag.dll buisness