Always look at group policy. But, unless all of the WIN 7s are in a different OU, then I don't see how.
Have you turned off the firewalls on WIN 7 or at least added AC or port 61067 on both TCP and UDP? Again, on a domain, you may not be able to turn off Windows Firewall, but you can make exceptions.
Also, and no one ever takes me up on this, but if you go to
www.experts-exchange.com, you can get a free six day trial. If you don't get the answer from the experts using SBS 2011, Firwalls, WIN 7 and Networking; I will personally pay you $25.00.
