When a user establishes a Remote Desktop connection to the server this connection will remain active until the user selects “Log Off” from the Start Menu. As such, if a user simply closes the remote desktop window when they’re finished with the server, that username will remain logged on.
The software running on the server to facilitate the Remote Desktop connection will allow for up to two simultaneous administrative sessions.
If a third attempt is made to login to the server, the error discussed here will be shown to the user, and they will be unable to complete the login process.
To get around this error and log into the server, you can log into a special session call the Console Session in order to Log Out the other connections.
To do this, simply type the following in a Start – RUN or Command Prompt.
mstsc /v:00.00.00.00 /console
Replace 00.00.00.00 with your server’s IP Address.
This will connect you to the Console Session on the server. Please use this session to only properly terminate the other two active sessions.