Administrators often access servers through Remote Desktop Connections. Sometimes an administrator forgets to log off, which prevents another administrator from logging on. Other times a process gets hung up so that further Remote Desktop Connections are impossible.
To determine whether a failed connection is the result of a forgetful administrator or a hung process, you can use Terminal Services Manager. Open the Control Panel Administrative Tools applet, and double-click Terminal Services Manager. In the left pane, expand the appropriate domain name under All Listed Servers, and double-click the server you want to view.
Next, select the Users tab in the right pane. If any users are logged on, look at their Logon Time and Idle Time displays. The Logon Time display shows the time at which the user logged on. The Idle Time display shows the number of minutes that have elapsed since the last keyboard or mouse input. If a long time has elapsed between the logon and the last input, the administrator might have forgotten to log off.
You can terminate a user connection by right-clicking the username and clicking Disconnect. However, because logging off a user from a session without warning can result in the user losing data, you might want to send a message to that user asking him or her to log off. To send such a message, right-click the username and select Send Message.
If there are no users logged on, a hung process might be causing your failed connection. To determine whether a process might be hung, open the Computer Management console and go to System Tools, Shared Folders, Open Files to view the sessions.