A customer has her network set up as a work group, but she has a computer with Windows Server 2008 R2 set up as a file server. Everything was OK until I reset her router (a SonicWall TZ150) I have reconfigured the firewall, and all computers including the server have Internet access.
I can ping from computer to computer, except to the server. The computers can see each other in the network browser. There is an entry for the server in the network browser, but selecting it returns "Network Path Not Found". The server can ping to other computers, but they do not show up in the server's network browser. The other computers cannot ping the server by name or by IP address.
If I reboot the server it is accessible for a few minutes, but then it disappears again. The server does not Lose Internet access.
I have turned on Network Discovery and NetBIOS over TCP/IP and turned off the Windows firewall.
What would cause the server to keep Disappearing?