I dont know if I did something while setting user permissions or it happened via SP2 updates.
After a nnn period of time of inactivity the screen goes back to logon mode.
XP Help Knowledge Base mumbles a bit about forcing users to log off in WIN2000 but I havent set any timers or run an exe file to do whatever the blurb stated.
XP is so much more stable than 98SE but it sure is frustrating to find how to do things for a small biz were Im the owner and IT staff!
The Auto Logoff features are accessible in "Control Panel>Power Options> [Power Schemes] & [Advanced] tabs".
The "Advanced" tab has a check mark placed next to the entry "Prompt for password when computer resumes from standby" - remove it & you wont have to logon on your return - but then neither will anybody else that cares to have a look at what is on your computer should they gain access to it while you run to the lavatory.
It's a safety feature so that no one else can use your computer when you leave it running (like to send a nasty e-mail to the CEO [read: Wife] in your name)! better to set the standby times at longer intervals (under the "power schemes" tab) than switch off the built-in protection completely IMO.