I paid for the pro version of limewire and my then computer crashed (not from the download - wife opened a virus). I had to completely reload windows and all my other software. Is there any way for me to re-download pro without having to pay again?

Check Upgrading to V 4.18 (click on link). Depends when you bought it. Of course you made a backup of the installer right?
You can check here: http://www.limewire.com/support/ top of page.