Hello, I have a Compaq sr2173wm desktop pc and would like to upgrade the video. What would be a decent upgrade for me? It has a pci-e slot. I'm running windows 7, 64 bit. I have a Geforce 8400GS card installed now. It's 512 mb and believe to be 32 bit. I have an upgraded 480w power supply. Could I go with a 1 gig card with 128 bit? Or would I have to go with a 64 bit card? Any suggestions would be appreciated.