I've bought GF8800GS and plugged it into PCIE slot. Then I started PC aaaand... NO SIGNAL. After searching through internet I've found that my motherboard is incompatible with 8800GS. Is there any way to make it work? Bios flash or something?
It is because it's a x4 PCIE slot? AFAIK, it should just operate at x4 (which would really really hurt performance- but should work). If what you are saying is true, then no, it won't work. But I have a feeling that it's something else, or a combination of things. Perhaps something faulty with the PSU.
I remember that problem. It's an incompatibility between certain VIA chipsets and PCIe 2.0 cards. Back then you could fix it by flashing the card with a BIOS that restricts the card to PCIe 1.0. Edit: Nibitor should be able to switch between PCIe generations.