I have the same problem. I have to enter registration code evertyime I start p3d. Everything is run as administrator, not in compatibility mode.
Then no, you don't have the same problem, at all. The OP said he doesn't have GSX in the menu, which means is not loaded, not that he had to re activate it each time so no, your problem is completely different and, it would be best if you opened a new thread, with a proper title, in order not to confuse other users seeing two different things discussed in the same thread.