Uninistall it again and find the Preferences folder and delete that (since I don't know were it is in Windoze, I suggest that after the uninstall, you run a Search in your comp for the keyword "Limewire" and delete all that comes up. However, it may not be the best thing to do, since, again, I don't really know XP).
Before reinstalling LW, go to
www.java.com and dld the latest Java. If you already have it, then it might be necessary to uninstall that too and redld and install it: it might have somehow gotten corrupt. (people have mentioned that actually going to an older version of Java has had better results so they wound up with two versions of the soft, but try just the newest version first).
Now, redld LW and install it again. See if it works.