FSX won't run since GSX license activated

[timd_chapman]

I installed the trial of GSX and it seemed to work fine on my FSX Steam edition so I purchased and activated the GSX/GSX2 bundle. Now when I run FSX it takes a long time to load the scenery then freezes on the task bar, I can hear the sound of FSX when I select it on the Task bar but it won't open as a window. The only way out is to kill FSX using the task manager.
Next stage was to check the integrity of FSX using the Steam tool and so called 'missing' files were downloaded. After this FSX works fine one time only, on a subsequent launch it hangs again.
At one time I had a message to disable default jetways in the control panel which I did but that did not solve the problem.
How can I make this work?

[timd_chapman]

I have now determined that if I repair FSX using the Steam verify function FSX will run fine the next time it launches. After that it will hang again until I repeat the Steam verify and repair process.
When FSX does run succesfully, after a repair, there are some configuration screens appear very briefly over the splash screen which disappear too quickly for me to read but it may be that SimConnect is being reinstalled or reconfigured.

[virtuali]

GSX surely works with FSX Steam without any problems and it cannot possibly be the cause of that slow loading. Very slow loading in FSX can happen for many reasons, but it's surely not caused by GSX.

Sometime I get very slow loading on a session, and a normal fast loading on the next one, without changing anything. The only thing you should not do, is to kill FSX with the Task manager.

Instead, when you realize FSX is running in the background, just press Alt-Enter once to put it in Windowed mode and then Alt-Enter again to go back to full screen. I think this is likely caused by not full compatibility with FSX and tha latest Windows updates, since FSX still uses DirectX 9, which is very old, and some features like full screen in DX9 have issues with the latest Windows updates.

Nothing that has anything to do with GSX, of course, since in FSX, GSX doesn't have any interaction with video drivers or DirectX.

[timd_chapman]

Thanks for the answer. Certainly your tip about using ALT and ENTER worked to put what I thought was a hung FSX into full screen, once this is done I can switch easily between full screen and window, it just won't launch in a window.
Thanks for your help.