VPN usage after Login

Being a complete rookie when using Sophos VPN I have some probably dumb questions but I can't seem to find any answers to them.  I have set up the VPN as directed and everything seems to be correct.  I'm able to connect to the remote network and the little traffic light is green.  Now I ask myself how to connect to the specific workstations on the remote network?  My first thought is let's use RDP.  So i do an RDP to one of the servers and it works perfectly.  Feeling good about that I now try to connect to a workstation and I run into problems.  No matter what I do it won't accept the user name and password for the workstation.  Works for Servers but doesn't work for workstations.  I have tried several workstations and no luck on any of them.

This makes no sense to me, but I'm sure that it is just something I missed along the way.

 

Any help would be appreciated.

Thanks

Ken Graser