Earlier quoted context omitted.
I have a really hard time believing that.
For the purposes of this reply, I'm talking about packages as distinct from Windows itself. A reboot is required if something you are trying to install is already in uss. Windows locks executable files and dells while they are being used, so it's not possible for an installer to overwrite them. When an installer detects this it places the new file in a temp store, and windows empties this store on startup, Thus if yo…
Restart Manager along with Windows Installer will manage stopping and restarting running applications/services to make sure that executables, DLLs, configuration files etc are updated atomically and transactionally.