Hi,
You need to refer to ASUS Website to update the BIOS and enable dual graphic in BIOS first. I also find a NVIDIA SLI PROFILE UPDATE 3 for you.
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I find the same issue as you encountered from the following link.
http://forums.nvidia.com/lofiversion/index.php?t51688.html
Note: Since the web site is not hosted by Microsoft, the link may change without notice. Microsoft does not guarantee the accuracy of this information.
Good luck!
Arthur Li - MSFT