Hi,
SLI is already working, the drivers just won't detect vanguard correctly, so heres a way to pass this:
note: The latest Nvidia drivers have a new profile, but I can't tell if they work since they're for vista only and don't support SLI yet.
First, download
nHancer and open it.
Next, click on Global on the Settings pane
Go to the SLI Mode tab and enter the following hex value:
402209.
Now, go to the SLI tab , and click on both the checkbox next to "SLI Load Balancing Graph" and the one next to "on".
The screen should flicker for a second.
Now load vanguard. If you see a green vertical bar on the left side of the screen, sli is enabled.
Hope this guide will work for you. Let me know if you have any problems.
Padishar