HELP!! XFX 6600GT Video Problems

[accsuperstar]

Hey guys, I have just purchased a XFX 6600GT card to replace my Ti4200. I have a L7VTA motherboard with 1 GB of ram and XP2100+ CPU. Since the switch, I am not able to view any videos or watch TV with my tv card at all. Everytime I try to, the computer just lags like crazy and the file wont eve play. I have DLed all the latest drivers (nvidia). Fast write is not on so I do not know what is going on. I can play games just fine however. Does anyone know what is going on? Thanks!