One of the things I figured out with Windows 7 and up is that when logging in over RDP an existing user would be disconnected unlike Windows XP that would logoff the existing user.
If you want them to logoff there are basically two options:
- Log them off through the task manager: Windows 7 – force existing user session to logoff, not disconnect, at log on – Super User
- Log them off through a script: batch – How can I automatically log out users from a Windows machine? – Super User
I will dig into the scripts one day as I’ve not needed this too often (I use Task Manager for now).