Having the power button on the login screen is good if you want to turn off your PC without logging in. Or, on the other hand, you might want to delete it for security or administrative reasons. The following shows how you can make the power button appear or not on the login screen in Windows 10 Pro or Home version.
Add or Remove the Power Button to the Login Screen
If you are running Windows 10 Pro you can easily add or remove power buttons from the login screen via Group Policy. Press the Windows key and type: gpedit.msc and press Enter.
In the Local Group Policy Editor head to Computer Configuration> Windows Settings> Security Settings> Local Policies> Security Options. In the right pane, look for "Shutdown: Allow the system to shut down without having to enter" and double-click on it.
Then on the Local Security Settings tab, set it to Enabled or Disabled and click OK and close from Group Policy Editor.
On Windows 10 Home
Because Windows 10 Home does not have a Group Policy feature, to add a power button, you need to hack the Registry.
Note: Making tweaks to the Registry isn’t for beginners or the faint of heart. Before making any changes to the Registry, make sure to do a full system backup or create a System Restore Point at the very least.
Press the Windows key and type: regedit and press Enter. Then go to the following path:
HKEY_LOCAL_MACHINE \ SOFTWARE \ Microsoft \ Windows \ CurrentVersion \ Policies \ System
You must create a new key and name it logout and set the Value to 1 if you want the button to appear or 0 if you don't want it on the login screen. Then close from Registry Editor. You don't need to exit or restart your system to function.
Just hit Windows key + L to lock your PC and hit Enter or swipe up for the login screen. There you will see a fully functional power button at the lower-right corner of the login screen.
Whether you want to make it easier to shut down your Windows 10 PC without logging in, or don’t want someone walking by turning off your PC, it’s good to know you can add or remove the power button accordingly.