I'm writing a new installer for our software, X. It installs into c:\program files\newversion. Because we can't be certain users aren't currently using the old version, we want to schedule the uninstall of the old version on next reboot.
So at the end of install of newversion, I want to schedule c:\program files\oldversion\uninstall.exe. It should run on the next reboot to guarantee no instances are running, and with admin rights so it can actually uninstall things.
After this, the scheduled task should be removed - no need to try running the uninstaller on every reboot.
Edit: Stack Overflow requests I add details. It seems like this question is as impossible to get answered here and on Google. I’m surprised Windows does not support an installer running a deferred action as admin on next reboot.