Chris,
There are a large number of events that take place in quick succession during a shutdown.
Choosing On disconnect from user session is as good a place to start as you are likely to find without complicating matters by setting up an Event viewer, Custom view to detect another event & trigger Task scheduler form there.- I don't know if it will work for you. These triggers are not well explained [
Triggers - MSDocs] and I don't know if the trigger is just before or just after the logoff.
- You will be tempted to set the task to run whether the user is logged in or not, to cover all bases, but the problem with that is that using that settings precludes running anything that appears onscreen [because only a logged in user can see a screen].
I can help you search for a suitable event to use as the trigger but it will involve using both Event viewer and a third-party equivalent called NirSoft FullEventLogView
To display what you want may or may not be possible. Only experimentation will tell.- Create the picture you want,
- Create a task [just a simple task for now for use in testing] to open that file,
- Right click on the task & select Run,
If it does what you want then it is a good baseline for working on the real trigger.
This is all a lot of work for something that will be less noticeable than a yellow stickie on the wall behind the desk.
Best of luck,
Denis