I had that same issue with a massive worse then being hung over headache
. I just went to the PX on base and bought 6 Windows 7 64 Ultimate disk. Lesson treat W8 and 8.1 like Vista. Sad thing is I live in Vegas as the USN has me assigned here and my neighbor is a MS IT. He said and recommends the same burn the 8
and reverse to W7 64 if your a FSX/P3D user.