P5W DH & SLi & Vista

Hi all, I'm afraid I may have just made a very expensive mistake.

I have a P5W DH Deluxe mobo, with an Intel E6700 C2D proc, Vista Ultimate is installed and I've just stuck in 2 x 8800GTS 640mb Nvidia's. Have I wasted my money?

Is it right that this mobo can only run crossfire not Sli? Vista is detecting 2 x Graphics Cards, but how could I check if a game is running SLi? I can see that the PCIe channel is running at 8x which I believe is correct for SLi.

I've just installed 3DMark06, what would be a reasonable score for an SLi'd rig? I'm currently scoring 9469 at 1024 x 768, no AA, optimal filtering.

I've seen other posts that are asking similar questions to this, but none were exactly the same, hence my asking. First time poster, so if you need more system info let me know.

Thanks

Big Vern

I read on similar posts that hacked drivers only went up to 79xx boards?

Also, if SLi doesn't work why is Vista recognising that I have 2 GPU's fitted?

Thanks,