You can find Microsoft Windows* Server 2012 driver availability for the Intel® Server Board S1200KP here:
We strongly suggest using validated components to minimize issues with your new build. You can find that information under the Compatibility heading on the Intel® Server Board S1200KP home page.
I will continue to keep their old server running until the Essentials RC is a full version product. By then intel should have a better idea on compatible hardware, drivers ect. Failing that I'll try another m/b.