I upgraded my video card from an ATI 3870 to a 5770, and the power supply from a 400w one to 650w. It's an MSI motherboard and im running Win 7 x64. Onboard video is disabled.
When I put the 5770 card in, the card isnt detected by windows, but it boots up fine. I set up remote access to the computer so I can see what its doing. I tried uninstalling and reinstalling the drivers, but still no card is detected. If I open up the software program SIW, no card is detected, but it shows the PCIE slot has the 3870 in it (when i have the 5770 in).
If I put the old 3870 back in, I get video ouput from the card, but Windows lists the onboard video as the display. The 3870 isnt listed.
A search for "msi 945gcm5-f v2 5770" turns up some other people that have the same problem. Looks like there's some issues with PCI-E 2.1 working in a PCI-E 1.x motherboard.
Time for a motherboard upgrade!