There's definitely no need to purchase again. Here's a link for where you can retrieve your serial number using your original Order number:
http://store6.esellerate.net/store/support/Default.aspxIf you don't know your Order number, enter your email address into the section labeled 'Finding your order number'. After that use your email address and order number at the top to have the serial number sent.
Or, you can email us at
support@splasm.com, providing your name and the email address used to purchase with, and we can locate your serial number by searching our eSellerate Order records using the info provided.