It says to install 4.9 I have to have service pack4. Can anyone tell me the reason why I have to have it? I just bought a 9800 pro, and it runs Counter strike source worse then my ti 4200 with graphics turned down LOWER then my ti 4200. I have tried everything possible except 4.9s with service pack 4 installed. I would try this as a last resort, but it always ****s up my PC when I install service packs. So, can anyone tell me why they make you install service pack 4 first?