Make sure that the XP firewall's configured to allow LW.
User Cant Connect - LimeWire

Then delete LW's preferences folder when LW's properly closed. See point 3 here & also point 2 if you've used older versions of LW in the past (there could be a folder in either location).
Fixes for LimeWire
This will kill all of your settings within options, you'll have to go back through afterwards & reset things. If you're not sure of your settings, go through LW's tools > options & write them all down, so that you can reset things later.

Your version of Java should be ok, but if you like you can try this latest Java update (works fine with my LW). Use the JRE offline installer & remove old Java versions before you install this one.
Java SE Downloads

You have "no port forwarding" in bold...does that just mean that you haven't tried port forwarding, or that you're not keen to try it (just to clarify)? There's a good chance that port forwarding would get rid of the firewall icon...if you want to have a try, either give us the model of your Belkin or find your router in the index here, choose LW from the list of programs & follow the instructions from there.
PortForward.com - Free Help Setting up Your Router or Firewall
Don't forget the step of setting up a static IP address, if that's included in the instructions. LW's listening port, port in the 'manual port forward' box & port forwarded within the router all have to be the same number

If you're still stuck, this has worked for some people.
http://www.gnutellaforums.com/connec...-problems.html