You have been ripped off, you have purchased a bogus copy of Limewire...
Limewire basic is free and Pro is US$18.88 with 6 months of free updates and email support...
If I where you I would get rid of that copy as it's probably full of spyware and all sorts of crap...You do this by using the unistaller in your Start > All programs > limewire unistaller....
Then download the free basic version from
http://www.limewire.com...
Try the tips in this thread for different approaches to searching files....
How to find music