The terminal server has exceeded the maximum number of allowed connections
When a user establishes a Remote Desktop connection to the WHS this connection will remain active until the user selects "Log Off" from the Start Menu. If a user simply closes the remote desktop window when they’re finished, that username will still remain logged on.
The software running on the WHS to facilitate the Remote Desktop connection will only allow for up to two simultaneous sessions. Active and disconnected sessions are calculated in this connection limit as is the Administrator account also. The console session, however, does not count against the connection limit.
If a third attempt is made to login to the server, the dreaded "The terminal server has exceeded the maximum number of allowed connections" error will be shown to the user, and they will be unable to complete the login process. You can’t even connect to disconnect the old sessions BUT there is a way around this:
Simply click OK to the error message and wait for unto 30 seconds for the window to close then simply type the following in a Start – RUN or CMD Prompt on your client machine.
mstsc /v:00.00.00.00 /f -console
Replace 00.00.00.00 with your server’s IP Address or server name. e.g.SERVER
Type in your administrator password. This will then connect you to the Console Session on the server and allow you to remote control the machine again.
Once in Click Start, point to All Programs, point to Administrative Tools, and then click Terminal Services Manager.
In the left hand column you should see your server name. Click on it once. Note the Users Tab in the right pane.
You should see a list of users. You need to reset the two "Disconnected" users. You can do this by right clicking the disconnected user and selecting "Reset." You should now be able to connect with RDP again after Start – Log Off.
When logging in under this special Console session always kill the inactive sessions first, because if you get disconnected again you will have to connect your monitor, keyboard and mouse.
Only use this session to terminate the other two sessions and not for any other use.
In future when you are done with a Remote Desktop session on WHS, you should always use "Log Off" rather than disconnecting by closing the RD window with the X as this will disconnect from the session but leave it active.