The Military uses the Golden Master Image for Windows. There are a few changes, most notably you activate with your CAC card. Not that many people know that and countless times I come across a computer that is complaining about being non-genuine. The Secret Computers are usually always like this. Put in your CAC card and click activate, and it is a genuine install.
If they heavily modified the activation code, you can bet they modified other parts. Just because it is approved does not mean it will be used. About 9 months ago we upgraded from Server 2003 to Server 2008R2. (Both Golden Master)
The upside is if you can get the install DVD, as long as you have a valid CAC card you have unlimited copies of windows.