Although I have Win8.1 Pro 64bit, my computer specs are similar (i7 @3.5GHz, GTX770 and 16GB RAM), I have not had this happen to me. However,
1) I run FSX in Windowed Mode all the time!
2) I have the frame rate set to Unlimited, and
3) FSX is always run using the Run this program as an administrator.

You could try that to see if it helps with your problem. Be aware that it takes a while to get used to FSX in Windowed Mode. ;)

NOTE. I don't like Win 8/8.1, so I mostly use FSX in Win7 Professional 64bit, but that's my opinion.  :-/