I have run into this issues several times before, where I am VPN’d into a client and have an RDP session open, and then my VPN gets cut off. When I sign back in sometimes I am unable to connect to the existing open RDP session. Today it was mission critical as I was almost at the end of a very long running process and I had to connect to the same session. After much searching I came up with the solution. It is a combination of two tactics that does the trick.
1. Use a command line prompt to connect to the console without disconnecting your existing session. In the command line on your desktop type the following:
mstsc –v:<yourservername> /F -console
2. Open up Task Manager on your server in this new session, right click on the session you want to reconnect to, and click connect.
Super easy once you know how!
I found the following two articles helpful in the writing of this post.