Besides the advice of 6_pac, I'd recommend to update your Java. Dowbload the JRE offline installer of the newest version from here:
http://java.sun.com/j2se/1.5.0/download.jsp
You might also consider to upgrade your lW, the newest version is 4.12.4. Download the basic installer from here (also offline installer exe)):
http://www.limewire.com/
By the way, the preference folder of the 4.12.3 version is not " .limeiwre ", it's called "LimeWire" and you can find it in the hidden Application Data folder (usually here: C:\Documents and Settings\Administrator.<your computer name>\Application Data\LimeWire ).
