Windows 7 64 bit problem

I had Vista 32 bit and purchased the windows 7. I did a custom install of windows 7 64 bit. The instal etc went fine I updated drivers and my bios is updated however on vista my performance scores are 5.3. The lowest score is disk tranfer rate @ 5.3, everything else is 5.9. On windows 7 I cants get it to perform and rating and it locks up when it gets to assessing disk part towards the end. The whole system isnt running well. I am not sure if there is something I am missing being that I have never did a 64 bit install. Maybe I misread something in posts and my system isnt compatible. I appreciate any help you can give me. I have:

gateway fx530xm
Intel Core 2 Quad Cpu 2.66 Ghz
4 Gig ram
2 - 250 hard drives

 

Make sure you have all drivers installed. Check in device manager and make sure you don't have any yellow exclamation points.