Update your Java (JRE) using the offline installer.
http://java.sun.com/javase/downloads/index.jsp
Remove your current version of Java & then install the new version.

Now reinstall LW & use it's offline installer too.
http://www.limewire.com/english/content/download.shtml

If those tips don't help, delete LW's preferences folder. See points 2 & 3 below
Fixes for LimeWire

Let us know if that fixes things:wink: