Windows 7: Domain Change - The network location cannot be reached.

I am studying Server 2008 at home. I had the Server up and running fine, had my PC desktop joined to domain on server easily with no problems. Also, had 3 other virtual servers and 2 virtual PC's joined to domain, VMWare. Then, for training, I decided to start over from scratch...
Re-installed Server 2008 on it's own PC. Then installed Active Directory and DNS. I had joined PC-Client back to the WORKGROUP domain and now tried to re-join PC-Client back to the Server Domain. I have the PC-Client DNS pointed to the server IP then try to join to the domain. I get a message ...

"The network location cannot be reached".

I can remote in and ping to the server but cannot join the domain. So, I decided to try to join a VMWare Client-PC (Vista) to the server....SUCCESS! Joined domain...! VM Client-PC (Vista) is running on the Windows 7 desktop PC.

I don't understand why my Windows 7 decktop PC cannot join the 2008 Server domain. While the VM Client-PC (Vista) can??

I decided to add DHCP on the server and I get an IP on my desktop from the DHCP Server. Still no success on joining domain..grrr
"The network location cannot be reached". <<< How is that? I get DNS and DHCP from the server but location cannot be reached??
I have IP via DHCP server, default GW pointing at server (thru advance settings on NIC) and DNS all through the sever. I am on internet now via the server but cannot join domain.

I've been working at joining my desktop to domain for 2 days now with no success, tried many sites for info.

Confused and frustrated on this minor problem, normally easy chore. Any help would be very much apprehiated. Thx in advance.