Try deleting your LW Preferences folder whilst LW is
closed; instructions here:
Point #2 & 3 in Fixes for Limewire (sample image included.)
If that doesn't fix it, then open Add/Remove Programs control panel, remove all versions of Java.
Then reinstall Java using only the "Offline" Java version from here
Java 1.5 (take the JRE)
Delete Prefs folder again.
Then reinstall LW using the "Offline" LW installer from herehttp://www.limewire.com/english/content/download.shtml