PC on steroids

Just thought I would Post this recent occurrence. I tried to play Robin Williams DVD on my PC and WMP didn't like it and put a message up saying my Graphic drivers were incompatible. I put the DVD into another PC and it played sweet as. I then decided to look at updating my Radeon drivers in the first PC. I disabled them in System hardware and then reinstalled them with the Graphic card CD. All seemed OK so to make sure the XP OS was operating in order I ran sfc /scannow. Wow, does this baby hum now. As I put on the title - it's like the PC is on steroids. Is this to be expected?? Neil