"Network" is not accessible. You might not have permission to use this network ERROR

Ok I kept getting this error when trying to install a new server on an existing network. So far I have worked out all the bugs on this minus 1.

 I turned off all of the firewalls, Norton and Windows. Shut down all the computer and brought them back up again. Blam it works every PC on the network can talk to the server execpt 1? The old server can talk to the new one, new server can talk to the old one and every computer on the network. But 1 of the work stations wont talk to the server. It will talk to the others on the network but not the server? Everything pings each other. I just can't access the new server from this one work station.

Any suggestions would be nice!

I've rebooted the machines a number of time still won't go?

Thanks