How-to: Implementing Idle and Disconnect Timeout Settings in XenDesktop
http://www.randyprice.org/2011/01/17/how-to-implementing-idle-and-disconnect-timeout-settings-in-xendesktop/
Idle Sessions:
To enable the Idle Session timer you will need to create a REG_DWORD value called Enabled under the registry key HKLM\Software\Citrix\PortICA\Session\IdleTimer. Setting this value to 1 will cause XenDesktop sessions to be automatically disconnected after a defined period of idleness. Setting the value to zero will disable the timer.
To define the number of minutes that a continuous idle state transitions to a disconnected state create a REG_DWORD value called MaxIdleTime under the registry key HKLM\Software\Citrix\PortICA\Session\IdleTimer. This value is reflected in minutes. For example if you wanted an Idle session to change to a disconnected state when it has been idle for 30 minutes you would simply set this value to 30.
Disconnected Sessions:
To enable the Disconnected Session timer you will need to create a REG_DWORD value called Enabled under the registry key HKLM\Software\Citrix\PortICA\Session\DisconnectTimer. Setting this value to 1 will cause XenDesktop sessions to be automatically log off the user after a defined period of being in a disconnected state. Setting the value to zero will disable the timer.
To define the maximum number of minutes to wait before logging off a disconnected state create a REG_DWORD value called MaxDisconnectTime under the registry key HKLM\Software\Citrix\PortICA\Session\DisconnectTimer. This value is reflected in minutes. For example if you wanted a Disconnected session to automatically log off the user when it has been disconnected for 30 minutes you would simply set this value to 30. That’s it!
To make this even easier I have created an ADM template for use with Group Policy to apply these settings to your XenDesktop machines.
http://www.randyprice.org/wp-content/uploads/2011/01/XenDesktop-Session-Settings1.zip