System Reboot Counter

[Der schöne Günther]

He does not want to block reboots. He has his application already registered in auto start, but does not want his application to run for the next two times the system boots.

Trying to get your application out of the "RunOnce" thing and then back in is the wrong approach, in my opinion. Why don't you just keep track of the reboot counter when your setup (or whatever it is) starts, and when your application launches, you compare if the boot count is greater than saved_bootcount + 2 . If not, just exit your application.