I frequently use Remote Desktop to access various PCs here at work
and nothing annoys me more than seeing this message box:
This is caused when “The terminal
server has exceeded the maximum number of allowed connections.”, right?
Basically, this happens because Windows by default only allows two simultaneous
terminal services connections to the same machine. If you see this message,
then there is already that number of people logged in, and you cannot connect
until one of the sessions logs off.
Usually what happens is that people
don’t explicitly log out of machines when they disconnect from remote desktop which causes their “rogue”
sessions to remain active. You could just nicely ask everyone if they would
please “log off” before disconnecting their sessions, but is there something
else we can do?
To perform the commands I am about
to show you, you need to be an administrator on the target machine. If you
aren’t you can’t perform these commands. However, in most development and test
environments, hopefully this won’t be an issue.
How
to query for users on a machine
First, how can we query to find out
what users have a session on a remote machine? Windows provides the qwinsta.exe
command which we can use to query for the sessions that are running The format
is as follows:
qwinsta /server:<serverName>
Here is an example running this
command against one of my local machines. Notice it shows the username, state,
and the ID of the session.
You can also use quser.exe:
quser /server:<serverName>
Here is the same example above but
notice it also when they logged in and how long they were idle.
How
to log a user off of a machine
Now that we know what users are on a
machine, how can we force one to disconnect? Again, there is a handy little
command called logoff.exe that we can use to force a user to log
off of a machine based off of their session ID. The format is as follows:
logoff <sessionId>
/server:<serverName>
Here is an example running this
command against one of my local machines. Notice that I used the session ID
that I found from the quser.exe command above.
Warning: If you remotely log off a
user, their log session goes away which could mean that the unsaved data is
lost, or if the user is in the middle of an activity, they may come down to
your office to chew you out.
