Make sure each LW is not using the same listening port. But if you cannot open it, right-click change compatibility mode to either Windows 2000 or NT (try both) & set to run as Admin.

We're just a forum here. And we are volunteers.

Considering the many millions of LW users, the numbers of people who will have problems will always be there. It's also not uncommon for a network of identically set up computers that LW refuses to work or connect on one of them.

How many firewalls you have there, sounds like at least two.