Try a clean install

Remove Java using the add/remove programs and limewire through start>programs>Limewire>uninstall

Then remove all traces of limewire (not your shared folder off course )
preference folder and incomplete folder. Do a windows search to see if there is anything left (splashscreen etc.)

Download the offline installers of both Limewire and Java (if you remember what version Java you were using before the upgrade, then try that one first)

Java

http://www.java.com/en/download/index.jsp

Limewire

http://www.limewire.com

install Java first (some advise to disconnect from the internet while doing it)