If the Session time out is not configured, or the logged on users are not available, you wont be able to logon to the machine. To overcome this limitation, follow the steps as below.
open a command prompt or type in the RUN prompt
mstsc /v:[00.00.00.00/SERVERNAME] /f -console
eg: mstsc /v:192.168.1.10 /f -console
mstsc /v:ADSURF /f -console
This will connect to the physical console session on the server (also
known as “session zero”). You will then be prompted with the login box
and provide the administrator details. Then you will be connected to the
Console Session on the server. Now you can reset the disconnected user
sessions from Terminal Services Manager. Please note that if you get
disconnected from this console session, you will have to go physically
to the machine.
If you have Windows Vista with SP1, Windows 7 or Server 2008, use the following syntax:
If you use the old switch “/console”, it will just ignore that and
proceed connecting. In Windows Server 2008, the /console switch doesn’t
exist anymore because “session 0″ is a non-interactive session that is
reserved for services. Difference between admin and console swtich are hxxp://blogs.msdn.com/b/rds/archive/2007/12/17/changes-to-remote-administration-in-windows-server-2008.aspx
You can also query the sessions on the remote machine as an
administrator of that machine. Open a command prompt as a domain
administrator that the remote machine is set to or map a drive of that
Then in the command prompt, type as below: (Windows Vista SP1 or Windows 7)
query session /server:servername
Replace servername with the remote machine name or IP address.
Now we have the information of all the users/sessions that are
active/disconnected on the remote machine. We can now reset one of the
session with the following command.
reset session [ID] /server:servername
Replace [ID] with the number from the prevoius output and servername
with the remote machine name or IP address. This will reset the session
and now you can login using Remote Desktop connection.