It seems that the original post that I made "GSX not working" is gone.
It's surely there, your mistake is that you are now posting in the "GSX Backdoor", while that thread was in the correct "GSX Support" section so, no wonder you are not finding it here.
Although I "noticed today" when FSX started that a scroll accross the top of my screen is stating "regenerating airport cache with a % of completion showing", I assume this is related to GSX.
This indicates GSX is working and it is updating its own cache. You need to check if it finishes. That message will stay on screen just for a few seconds (not until it completes 100%) so, pressing CTRL+F12 again, will show its current process. While it's updating, you can't use GSX services and the GSX menu will not appear. After it completes the cache at 100%, GSX menu should work.
However, it's possible that for some reasons related to problems to your Windows account permissions, it might not save the updated cache so, it will still try to re-updated it on the next FSX run.