The Deployment Server components lets you execute tasks (inc. power control/shutdown) on network machines, assuming you have a Deployment Server solution set up on your NS.

If the DS components aren't up your alley, you can use the ASDK Task solution and some components generated against the Task WS. I've posted an article about how to accomplish this via WF, stay tuned for when it gets approved.

Here is a link from Microsoft reg."How To Force Users to Quit Programs and Log Off After a Period of Inactivity in Windows XP"

http://support.microsoft.com/default.aspx?scid=kb;...

Thanks,
Sid

I posted an article about Lock Workstation During Installation and Deployment.

Maybe it help you to force the logoff using a DS or NS task.

But if you have a business environment with Active Directory , I suggest to use the Group Policy Management and setup the automatic screen saver after xx minutes of inactivity with logon.scr ( Screen saver with logon password )

Paolo

Here are some more links

http://blog.case.edu/djc6/2005/03/09/automatically...

http://www.computerfreetips.com/windows-xp/Compute...

http://security.yale.edu/tools/scr.html

Thanks
Sid