Just figured that out, now if I could only find the purchase email. I've had GSX for a long time and can't remember which email I used to buy it.....
The FAQ page of our site:
http://www.fsdreamteam.com/faq.htmlAssuming you have access to all your emails, you might try with each one on the Esellerate site: if it's the wrong one, they'll tell you.
If it's the right one (Esellerate page will tell you the Order History has been sent), but you have lost access to it, then you might contact us to the support email (the "Contact Us" page of the site), indicating the previous email and to which new email you want the order to be associated now.
Also, don't forget that when you first activated GSX, it saved a backup registration file ( .REG ) in your Home folder (the folder with your name, usually under C:\Users ), which can be used to reactivate without having to type the Serial Number or requiring access to your purchase receipt: just double click on the .REG folder to insert your Serial Number in the registry, so the sim will prompt to activate on the next startup.