The settings within MTP that worked for me:
Go to Firewall; Settings
Smart Advice and Advance Settings: Enable Smart Advice, and Allow ICMP ping request and Enabel UDP tracking.
Ports and System Services: I had to enable Microsoft Directory Server Port 445 and Windows File Sharing(netbios) Ports 137-139. Common Operatin Ports Local TCP/IP Port 5357 is on as well Universal Plug and Play Port 5000, 1900, 2869. I then could get two Vista machines to talk.
Hope this helps.
you've been absolutely right with your recommendation. It helped me a lot to get back to the internet.