Windows 7 Cannot See Server

Just installed my first Windows 7 PC. It is the 64 bit ver. Works like a charm, very impressive BUT.I cannot get it to attach to our DOMAIN. It does NOT see the server.We have a windows 2003 server. 5 PCs are attached to it through a hub. Internet is through a cable router which is attached to the hub. The cable router acts as a DHCP server, and the new Windows 7 machine has an IP address within the scope.All 5 of the PCs are Win XP and have no problem attaching to the domain and the server can be seen simply by Opening Explorer then going to My Network Places.The Windows 7 PC found the Internet immediately and there is no problem surfing the web.On the Windows 7 machine it was defaulted to Home Network. When I try to change it to a DOMAIN, no matter what I do it comes back with "The Network Path was not found".I also use the wizard which tries to connect to the domain through different means
and while it does come up for username and password it still rejects it in the end the same errors as above.

I also have tried all of this both with the firewall enabled and disabled. At present I have the firewall fully disabled. I've tried everything....used the workstation username, the administrator name....all the same results.Now here's the weird part, if I fiddle around enough in the network discovery window for whatever reason after a while suddenly the server and the other XP computers appear on the network. I have not been able to find out what it was that I was doing that click this or if for some reason there's something that just triggered it.However once this happens if I reboot the computer it goes back to the way it was and I have to go through this all over again clicking things and refreshing in the network window until suddenly it starts again and then I can use the network all until it might disappear at some other point.Still even when the network can be seen and the server can be seen I still cannot change from workgroup to domain.

I can ping the server by the IP number and the server name.I can paying an XP workstation by its name or IP address but only if I turn the xp workstation firewall off.Reading on some of the other forms somebody suggested to turn off the network adapter Internet protocol version 6 under the adapter properties. I did this but it didn't really have any effect that I could tell.However one thing that seem to make it easier for me to see the network was by going into the IP version 4 properties and clicking on the "use the following DNS server address" and inserting the server's IP address. I also went into the advanced settings to the DNS and insert it again the server's IP address also added under DNS suffix for this connection the name of the domain.I am completely out of ideas at this point I do not understand why I can't change to a domain name, nor why I cannot see the server without a lot of clicking and hitting the keyboard.