There's a big, nice, "Deactivate" button in the Addon Manager that does JUST that: it removes your activation. However, there's something in your report that doesn't look right.
I installed a product that uses addon manager, but before registering decided I did not want to continue so I uninstalled. Now I keep getting a prompt to register it!
Are you *sure* this description is accurate ? You said "before registering". If you haven't registered yet, nothing is placed in your registry, and the program will work in Trial, and it will NOT ask you anything.
The only possible reason why you are being asked to register, is if you *already* registered a Serial Number, you changed your hardware, but you haven't reactivated it for some reason, for example if you couldn't connect to the internet and decided to continue without reactivating it.
So no, it's not possible that you are being asked again for a registration "before registering", since nothing is stored in the registry UNLESS the activation succeeds.
This is the NORMAL operation of the program.
The OTHER possible reason, is if you or a software you ran (not an official FSDT software, of course) placed a FAKE/BOGUS Serial Number in the registry, so the Addon Manager see there's SOME Serial, which is not active (of course it's not, since it's not possible to activate a fake Serial Number), will try to activate it, and since it will fail, the request will be made at each FSX startup.
In this case, you'll have to manually remove the bogus Serial from the registry, using REGEDIT, under the HKCU\Software\fsdreamteam, you'll find all the keys for our products.
