Do you still have the installer? Keep it .. do not trash it!

Follow these directions but instead, use your own Pro installer you downloaded: http://www.gnutellaforums.com/333278-post2.html
Also delete your old preferences folder before you install ... most likely step 3 Fixes for Limewire (click on blue link) though possibly step 2 if step 3 does not apply to you.

BTW always good to see experienced users around the forums, no matter how often you use the program.