I have following scenarioWindows Server 2003 as domain controllerWindows Server 2003 with Active Directory and DNS installed (integrated). Have IP address 192.168.10.5 subnet mask 255.255.255.0 Gateway 192.168.10.10 (ISA Server). DNS 192.168.10.5 (DNS forwarding has been done to ISP DNS) Domain name is mydomain.local this machine has only one NIC card.Windows Server 2003 with ISA serverAnother machine Windows Server 2003 on which ISA server is installed have two NIC (internat and external) Internal IP address 192.168.10.10 Subnet 255.255.255.0 No Gateway. DNS 192.168.10.5 External NIC join to the Internet. This server can(has)join domain controller as a member server. ISA firewall rules has been set to access Internet for internal clients.Problem:I can join any Windows XP machine to my domain mydomain.local and can even access internet. Can ping to DNS server and domain controller, No broblem, the problem lies with Windows VistaExtreme edition.I can even ping IP address of DNS and Domain controller from Windows VistaExtreme (as workgroup) and can have access of Internet. Vista IPv4 setting is 192.168.10.21 mask 255.255.255.0 gateway 192.168.10.10 (ISA server) and DNS is 192.168.10.5(active directory integrated DNS). I can ping all these IP but when I try to join domain mydomain.local (or simply mydomain by netBIOS name) Window Vista is giving error network path not found/reached. I check all IPv4 properties like enable /disable NetBIOS over TCP/IP, enable/disable IPv6 also, but same problem exist. Not only on one machine but 3-4 Windows Vista machine same issue. I am using one of the Vista machine behind ISA server (as said above) to post this problem.Please help me to solve this problem.

I left the computer on with Windows Vista, enable the file and print share in TCP/IP properties of Windows server 2003 fornext day. Now I can see the server in my network places (in workgroup) and can join the Domain easily. But still could not figured out what the problem before. Windows networking can be strange sometimes and required time.Thanks !