Do you use DHCP on the network or do you assign static IPs? If they are static, add the DNS servers to TCP/IP properties of the network card on the workstation then try again. If you use DHCP then make sure it assigns the DNS servers (which should be the IP address of the DNS server on your network).
If you open a command prompt on the workstation and run the following command then it should show the server address as the primary DNS server:
If not, that's the problem. Let us know how you get on.
Dave