Terminal Services using RDP is great for sharing a computer among multiple users who may be dialing in from a remote location to use the resources on the network. However, if a user forgets to log out after they use the computer, the next person won’t be able to log in until the last user logs out of the system. You can make the terminal server automatically disconnect if the user does not use the system for a set period of time, thus allowing other people to log in and use the system resources.
From the remote workstation start the Group Policy Editor.
Go to Start –> Run and type mmc in the run dialog box.
Load the Group Policy Editor
From the File Menu, click Add/Remove Snap-in. Choose the Group Policy Object and load into system.
The settings are located in Local Computer Policy\Computer Configuration\Administrative Templates\Windows Components\Remote Desktop Services\Remote Desktop Session\Session Time Limits
The settings you need to change are
Set time limit for disconnected sesions
Set time limit for active but idle Remote Desktop Service Sessions
Terminate session when time limits are reached.
NOTE: I do not set the Set time limit for active Remote Desktop Service Sessions value. If you set this value, the active users will be disconnected from the session after the time out value is reached.
On Windows XP computer, the values are found in Local Computer Policy\Computer Configuration\Administrative Templates\Windows Components\Terminal Services\Sessions