IT is never listed on the program of LW Pro. You will need to check thru your lists of emails to find out. If you recall, you received an email with a link ti your Pro personal downld page. WIth luck you still have this email. Else go to LW support page & enter your emails & hope for the best.
http://www.limewire.com/english/content/support.shtml Else, send a message to
limenathan (click on link) with all your details including purchase date & receipt, payment details, email addresses, etc.
Many people will bookmark their pro downld page so they don't have this problem.