I would like to add too i installed GSX at the end after all my addons both aircraft and scenery, as well as squawkbox, asn and ultimate traffice too. The sim ONLY started doing this after gsx was installed. Therefore its GSX and not the others... How can now fix this "stop working problem"
You just can't assume "it's GSX", JUST because the crash happened after installing it. For example, if one of the other add-ons you have installed have caused a problem to one of the Windows libraries needed by GSX, you would mislead thinking "it's GSX", because the problem surfaced only after GSX tried to install its own (correct) version.
Don't you think that, if GSX really "crashed FSX" after a clean install, we would have *thousands* from users reporting it, and the problem would have been found and fixed years ago ?
So, in order to find what really crashed, you should first check the Windows Event Viewer, under the Tools section in the Windows Control Panel. Look in the Application Log, there should be some events related to FSX, open the Event, check the Details, and post them here.