I have a user with an old XP box that I virtualized. It is running on Server 2012 Hyper-V. It has a frontend program that talks to an old Server 2003 box that I virtualized long time ago also on 2012 Hyper-V, tho it is a different host. Before I virtualized the PC the user would RDP to it, run her program that touches the server VM and do what she needed. She is the only user that needs access to the frontend virtual PC or the server (tho she never accesses the server directly).
Since the box was XP I hoped that I could use some combo of Private and/or Internal network setup in Hyper-V switch manager to keep the XP from being exposed to the internet after MS retires it.
Not sure how to do that, till now all my virtual NICs have be external only.