Hiya Exodus225, and welcome to the forum
If you still have your purchase receipt, or some other proof of purchase, you can email Vstep at info@shipsim.com and explain the situation to them
If you have the game currently installed, you can use the file located in the topic below, to recover your licence key:
http://www.shipsim.com/ShipSimForum/index.php/topic,2098.0.html
Regards.
Carl.