Were there any errors reported when LimeWire was installing? Did Java 2 Install correctly? It's in your Add/Remove Programs list on Win 98, but I can't remember if it's called the same thing in Win2k or not. If Java is not in the list, go to
http://java.sun.com/j2se/1.3/jre/
and download the approriate installer. Install Java again (after having uninstalled the previous installation FIRST) and try it out.
If this isn't the case, feel free to post again! :-)