What's the best way to allow an administrator access to a locked user XP session, preferably with a logged event? The goal is to allow admins to cleanly shutdown/save existing work when work needs to be done on the PC. I am aware of the various VNC software flavors, but that only works when the PC is unlocked. Resetting the user password on the DC doesn't work either since the unlock password is cached locally, which means you still have to log the user out and possibly lose work.
I have not tried it personally but there is this:
http://www.codeproject.com/KB/system/RemoteUnlock.aspx
W/o a clever hack (described by Nathan) windows intentionally makes this difficult.
They way I read about it, When you login windows create a security token to lock your 'login session' handle, and it's only accessible from the user who created the security token. Administrators can only discard this token, they cannot access it. (I may be getting the terms wrong, it's been a while since I read this)
Even the RemoteUnlock tool described by Nathan admits it doesn't "Really" unlock the workstation, it just 'tricks' windows into switching back to the 'default' desktop; the security system on windows still thinks it's locked.