I have a new Windows Server 2008 domain controller and I'm in the process of joining our workstations to the domain and granting them access to the new file server. I've had problems accessing the file server from a couple different endpoints. Right now I'm looking at one that's located at a branch office that has a VPN tunnel back to corporate. When you try to access files on the P: (public) drive you get various error messages, also while trying to open up a file the computer because non responsive in general. An error I’ve gotten a lot is “There was an error opening this document. The specified network name is no longer available”. I can ping the server just fine and can browse around the folders without a problem, but I can’t open any files. I don’t have a problem if I sign in as the same user from my workstation. Also I’ve found the problem persist if I sign in as the Administrator from the problem laptop. I have removed my antivirus software, rejoined the domain, and confirmed there are no firewalls running. Any troubleshooting advice?