Turn off the Windows Firewall running 2 firewalls is not recommended they can have conflicts with each other.Then follow the instructions in the links below for configuring your Firewall if that doesn't get rid of the brickwall follow the instructions for Port Forwarding your Router.
McAffe http://portforward.com/english/routers/firewalling/McAfee/McAfeeSecurityCenter/LimewireIn.htm
For some reason it wont let me insert 2 links to the same web site just copy and paste the URL into your browser
Linksys http://portforward.com/english/route...LimewireIn.htm
I do not know about your router but with mine you can also set up forwarding for UPnP you just go the application and gaming page and you will see UPnP forwarding. I have found that with different versions of LimeWire this sometimes has to be set up.