Windows 8 + FSX = Constant crashing.

We just have to guess without knowing your system specs.

1-If you loaded something new, aircraft, scenery etc. that could be the cause and you should delete it and see how you do.

2-Overheatingh (my favorite).
FSX is graphic intensive so it pushes the computer.
Open it up and clean out the fans concentrating on the CPU fan.
If you never cleaned a computer, ask first or just Google it. If you don't you could burn out the computer.

Let us know how you do.

Overheating isn't a problem as when I run the game in compatibility mode Windows 7, it doesn't crash, but the problem with that is that it'll lag heavily when I have the sound activated, but when I deactivate the sound then I'll get a steady 25 FPS.
^ Only occurs during Windows 7 Compatibility mode.

+ I cannot think of any scenery I've recently downloaded that will cause this incident, but I'll guess I'll reinstall the game just to be sure.

OK, let us know.

I have had countless crashes since installing FSX Gold on Window 8 also.
Things seemed to calm down when I unchecked the Preview Direct10 option. Crashes where less frequent.

Sounds better but it shouldn't crash at all.
At least you can use it now.

Also try this - - it may help - -
RightmouseClick on your FSX desktop icon. A pop-up menu appears.
Select the [Run with graphics processor >] and change the options there.
See what difference that makes.

Select the [Troubleshoot Compatibility] and go through process to find best compatibility mode for your system and FSX