Make sure your Java's up to date. You can download the latest JRE update here. Use the offline installer
http://java.sun.com/javase/downloads/index.jsp

Have a look through the threads below, there are a few things to try
http://www.gnutellaforums.com/showth...computer+slows
http://www.gnutellaforums.com/showth...computer+slows


As for your search results... how many green connection bars do you see? Do you see the firewall icon (brick wall)? No guarantees that it will fix things, but you could try deleting LW's preferences folder when LW's closed. See points 2 & 3 below
Fixes for LimeWire