Application restart #1

I'm a pretty carefree guy, experimenting with all kinds of weird applications from dubious sources. The domain and the network is pretty well secured, but my virtual lab computers are like people in the old west; unregulated and easily killed off if they become to unwieldy.

Still, when something suspicious happens I wan't to know why, because of course I wan't.

Some time ago the following dialog suddenly popped up when I logged in to my work computer;

What? No, I would not like to allow Regedit.exe to make changes to my device. Searching through the startup locations with Sysinternals excellent Autoruns didn't reveal anything and concurrent logons did not start Regedit.exe. Probably, it was launched by the RunOnce registry key. Difficult to troubleshoot when the traces are gone.

Weeks later it appeared again! What program is causing this? Why does it want to start Regedit.exe? How do I find out when it only happens once every month or so? None of my coworkers have had the same experience and even though I have a black belt in Google-fu searching the web was hard, only resulting in how to use Regedit. I know this already!

Then it appeared on my clean virtual lab computer, not in any way related to my domain joined work computer. Luckily I had just done a snapshot of it and Regedit.exe wanted to start every time I restored. Finally some progress! Using my incredible skills I finally found the culprit using Procmon, the greatest tool of all time;

Indeed it was a RunOnce registry key and the name of it, "Application Restart #1" is the clue. Since some version ago (who knows which, versioning sucks) Windows restarts select applications that were running when the computer was shut down. Not only during forced restarts from updates, but when you manually shut down the computer. Apparently I am not very good at closing programs before shutting the PC down.

Not all programs are restarted and how Windows decides this is still a mystery to me. It's a badly documented feature with a badly thought through workaround. This is what Microsoft Answers says about it.

Regardless, Regedit.exe, or any program requiring elevation, should not be started automatically!

Or is it requireing? Require-ing? Reqiruing? My Google-fu might not be as advanced as I thought.