I'm guessing here, as you give no details of your set up atall ... This might be a java issue, See
http://www.gnutellaforums.com/showth...hlight=cpu+100 Grandpa's post is very good.
Also if you are trying to start Limewire with a large number of incomplete downloads in the download window, this can happen. It is not a good idea to do this.
If these do not help please give us some details and we can then take the guesswork out
This post will explain what details we find helpful .. some are irellevant to your problem but we have the same questions for everyone.. There are no favourites