Could be a corrupted installer if it happens while in the process of installing. You could try and redownload the installer exe to your desktop from here:
http://www.limewire.com/
If LW is already installed and it happens after starting up the program (already some time ago that I had to install it, though not usre whioch of the both it is), then it might be a corrupted Java installation. To fix this you need to uninstall all Java versions, reboot, download the JRE offline installer of the newest version from here:
http://java.sun.com/j2se/1.5.0/download.jsp
Install it, reboot again and then reinstall LW.