Hi.....Did you purchase Pro over 6 months ago?? If so you will have to purchase it again...Pro gives you 6 months of updates and tech support after that you may keep using it, but you do not recieve any updates or support...
It's wise to back it up to disc, because as you have just experienced if you crash you loose it...
Make sure you only get Limewire from the official site as well, it's $18.88US...
there are many scam sites around that take your money and offer you the basic version (which is free).....
http://www.limewire.com