Reinstall Java. Use the JRE offline installer. Remove your old version of Java before you install the new one.
Java SE Downloads - Previous Release - JDK 5
Delete LW's preferences folder when LW's properly closed. See point 3 here & also point 2 if you've used much older versions of LW in the past (there could be a folder in either location).
Fixes for LimeWire
This will kill all of your settings within options, you'll have to go back through afterwards & reset things.
Now reinstall LW & make sure to use the offline installer (not the recommended one).
Lime Wire » Download LimeWire