George,
This was the method we used for two C apps running on that were DDE servers to an InTouch application. Even though Windows is not the initiator of the message, which it did when you closed PROGMAN (and I assume the Shutdown sequence in Win 95/NT does this too), apps can use it to find out if another app is able to be shutdown. The response does depend entirely on what the app has in it's OnQueryEndSession() event handler, by default it says yeah I can shutdown, but it might not if the app has conditions which would prevent it.
>I thought that WM_QUERYENDSESSION was for shutting Windows itself down, not terminating other applications. While that would be part of the shutdown procedure, it wouldn't be something that would actually be occurring here. Am I incorrect about this?
>
>One other possible problem. The message parameters are different for 95 and NT.
>
>BTW, I agree about sending these messages across the network.