Unlike Windows 7, Windows 10 (and 8.1 before it) comes with ‘Fast startup’ enabled on systems that will support it.
So what’s that then? When you choose the ‘Shut down’ option, what actually happens is that some core system files are written to disk in the state they are so as Windows 10 does not have to spend the time loading them from scratch the next time round.
Isn’t that like hibernate? Well, yes, it partially is!
So, on an out of the box Windows 10 system, in order to truly reload your Windows from scratch you must select ‘Restart’.
Is there another way? Always!
Go to Control Panel\All Control Panel Items\Power Options\System Settings and click on the ‘Change settings that are currently unavailable’ shield. This will now allow you to un-tick ‘Turn on fast startup’, ‘Save changes’ and your ‘Shut down’ option will truly shut down.