I'm trying to implement a script which shuts down a Windows 7 PC if nobody is logged on. I have it running as a Scheduled Task.. all works fine, BUT if a logon is in progress (ie on the Welcome screen) when the script runs, it appears to believe nobody's logged on.. is there a variable/reg key which is set when a logon is initiated? Alternatively, could there possibly be a "time since last user interaction" or "time of last user interaction" variable which I can make use of? Thanks in advance!

Check the event viewer. It has several events that get recorded the very moment when a logon process commences.

Ooh, great idea!! I only remember the event viewer when tracing faults!! Thank you!