Detecting User logon/Logoff events for a Windows Service

Question

I have written a windows service that needs to perform certain functions only if a User is logged in. The problem I am running into is that I get an error if the computer is in the process of being shut down or restarted. At all other times, the service runs just fine. I need to either detect a logon/logoff event OR check somehow as to whether there is currently a valid logged on user. The closest I have found is ManagementEventWatcher class, but I am not able to determine the appropiate event class to query for the Audit logon/logoff events. Basically I just need to not try and open the ad-watch if the user has logged off (Event Id 538). Of course, if there is an easier check, please let me know of that! I do appreciate any assistance on this. Thank you!

roriddle · Answer

Because shutdown or boot are in process the computer will not respond to most outside requests. Until windows is fully loaded you cannot expect to get much from the computer.