You need to use the email address you purchased Pro with, but if you paid for it over 6 months ago, or if you paid any price other than US$18.88 you are likely to have purchased from a scam site.
go to
https://www.limewire.com/sales/engli...rms/buypro.php and click "already bought pro" at the top
I hope this helps
and please remember in future that you should back up all valuable files and programmes onto a disc or separate hard drive in case of computer disasters.