I had the same problem and did a zillion things and nothing worked until i tried this:

Go to Start My Computer
Go to c:\programs\program files\limewire
then click (or double click) on the file that reads
limewire.jar
(and under it says executable jar file, about 7007 kb)

After I clicked that it brought me through the setup stuff that's real quick and easy and everything worked great after that!

Oh deselect start limewire at startup. I heard that causes problems too.

Good luck! (I almost deleted limewire and was just about to use something else than this worked. I think it knew it was in trouble.)