Check to be sure you don't have any virus. Scan your computer.
Otherwise:
1. Delete your LW preferences folder whilst LW is CLOSED:
http://www.gnutellaforums.com/genera...der-vista.html
2. Uninstall Java.
3. Uninstall LW using the Start menu > All Programs > LW > Uninstall.
4. Run this utility:
Crap Cleaner
5. ReInstall Java using the OFFLINE installer only:
Download Java software from Sun Microsystems (about 15 MB in size)
6. Reinstall LW using only the OFFLINE installer:
http://www9.limewire.com/download/LimeWireWin-full.exe