Shutdown vs Restarting after installing programs

It is recommended to restart after installing software or editing system files. So what about shutting down or logging off? Will the same changes take place?

In the days of old, restarting was 100% equivalent to shutting down and then powering up again. As far as Windows is concerned, at least.

However, nowadays Windows has a feature called “Fast Startup”. IIRC it is enabled by default at least on desktop computers. It changes what shutting down does; instead of shutting down, you are logged out and the system then hibernates. Then when you power on again, it will not boot but rather resume.

You can make sure you are actually shutting down regardless by holding Shift when activating any of the Windows shut down buttons/options.