Windows 8 can't detect my second GPU

[Area 66]

Well on my MIVE Z I was using 2 x 560 in SLI with Windows 7 , I remove one before I install Windows 8 , and now I return the second one and no way Windows 8 can't discover it, I Google a little bit and no one have a solution, WTF. I give my self 24 hours to find a solution before I re-install Windows 7 . This is will be a major step back if SLI don't work with 8 , any idea ?

[Chino]

Are you running the latest BIOS for your board?

[Area 66]

the BIOS is updated, I found another thing to fix the drivers not show, I'm gone try all of those next week as for now I place the second GPU on another PC for fold.

[Area 66]

FIXED. I put back my old HD with Windows 7 ( was in storage for few month in case I want to revers back ) and I still have the same problem, I said WTF I have a slot defective, I go in the bios under GPU.DIMM Post, and guess what the 4th slot was NA,, I try the GPU in all other slot and it was working, SO I inspect the slot 4 and one of the tab was bent and lay down at the bottom of the slot. SO I use a needle and my bino and I redress it and put back in place. So now I'M back in business. Honestly I don't see how this tab get bent like that, the upper part seem to be broke, so I guess it's a manufacture problem. Anyway i'm allergic to RMA so I keep it like this, if one day this tab broke definitively, I will use this board with a single GPU.