This problem happens because Windows only allows two remote terminal services connections when you are in administrative mode, and you’ve either got two people already on that server, or more likely, you’ve got a disconnected session that still thinks it is active.
If you happen to be at the same location as the server and can physically log into its console then you this is fine as you can log in and clear the connections. However, things can get a little more annoying if the server is at a remote or client site.
Open a command prompt and type:
mstsc /v:11.22.33.44 /admin
or
mstsc /v:11.22.33.44 /console
Replace “11.22.33.44” with your server’s IP Address.
This will connect to the physical console session on the server, thus temporarily getting around the session limit. Please note, however that you may only get one chance at this and if you get disconnected from this session you may have no choice but to physically go to the machine. Therefore, once you get logged in, go straight to Administrative Tools, open Terminal Services Manager and clear those pesky logged sessions! 😉