Windows 10 Compatibility Issues Forcing US Air Force To Scrap a Significant Number of Computers (betanews.com)
The US Department of Defense has decreed that the Air Force must complete its migration to Windows 10 by March 31 2018. From a report: Failure to do so will result in any systems not running Microsoft's latest operating system being denied access to the Air Force Network. However, because Windows 10 is not compatible with many of the Air Force's existing systems, a significant number of computers will need to be replaced in order to hit the deadline.
Win10 is not much different than Win7 in most respects. You can completely ignore the Metro interface for the most part, unlike in Win8. Win10, at this point, is equal to or superior to Win7 in many respects.
pcmcia cards
I thought these things were a myth.