Make sure this LW is not using the same connection ports as any of the other computers. The router will only accept one port per computer and per application during a computer session.

I presume you have tried the connection fixes?

Did you set Java to Run as Administrator? Seems to be important for connecting issues with at least Windows 7 or later. Search the Java.exe file and right-click and choose Run as Admin. This can also be done via choosing properties.

Is there a 64-bit Java 1.6? My thoughts were they were all 32 bit or the 1.6 is no longer available for 64-bit java. Other than administrator settings, Java should not normally be an issue for LW 4 versions.

Sometimes a reboot can help sort connection issues out. Particularly if you installed a fresh connection file.

Other thought, is with LW 4 I always needed to disable some of the advanced options -> performance options, in the preferences on a Mac computer for it to connect. Usually TLS was the problematic issue. As soon as I disabled that option, LW would connect within a minute. http://www.gnutellaforums.com/connec...t-connect.html

BTW if you want to check to be sure a particular port is open on the computer at a particular time, try this tool www.canyouseeme.org which seems to work quite well. Particularly helpful for checking port forwarding has worked. Just type/copy-paste in the port number you wish to check.

As for UPnP abilities, LW can be a little slow at times for it to finally communicate properly with the router and a port be opened. This can be slowed down by large shares, lots of incomplete files, etc. as LW loads them when it opens.

Double-check LW is on the computer's firewall allowed/exceptions list. And possibly any other security software for that matter, since some can block LW without reason.