Had this HTPC based on p4m890 via chipset that worked quite well. Wanted to enhance it's video performance so I tried adding it 3 different Nvidia cards I had (8600gt, 8500gt and 7200gs) and non of them worked under windows 7.
I replaced the board to another one I had (nvidia 570 ultra chipset) and the problem remained (Black screen after booting into windows 7).
I thought it's a fault of the OS, So I've installed windows xp, And after installing a driver from 4/2011 - It went black screen again after the reboot.
I'm afraid it has to do with some chipset compatibility, But not working with p4m890 AND 570 ?????