Works fine for me too...Win 8.1 Pro...

In regard to windows 8 64 bit running it has a wonderful way of turning off USB devices I found this a bit annoying as I thought it was just  a glitch in FSX. Energy efficiency is the windows 8 plus but annoying for us simmers in mid-flight when you realise your yoke won't respond because windows has turn fit off to be energy efficient. Once I searched up how to disable as much energy management that s=turns off USB devices etc etc. Very stable FSX environment note Im using Mac Air running bootcamp with "Haswell Chip I5". Done some very long haul flights in PMDG 777 and stable operating system. 

 

I have no desktop crashes freezes or any unpredictable system actions....Since late last year.