I am having the same issue with my Pc as Jamesday25. I have and A8N-SLI asus motherboard with and nforc4 chipset and an AMD ATHLON 64 4000 CPU.2gb ddr1 memory. This board is about 4 years old, but it has not been a problem ever. I had installed 2 8800gts video cards about 2 months ago. I decided to upgrade my system to 2 geforce 250GTS 1GB cards and run them in SLI MODE.When this problem first occured i did try each card separetly, and both work fine by themselves.I have kept all drivers up to date with my past cards. This whole problem did not start until I went back to a 1 video card set-up. When I tried to go back to SLI, it seems now that windows does not want to show 2 cards in the device manager,even though they were running fine 2 months ago (meaning the 2 8800gts's).Who out there has the fix for this problem?