If you tap the Win+L keyboard shortcut on your Windows 10 desktop, it will lock your system. If you have a password or PIN set up, you will then have to enter it to return to your desktop. Depending on your screen settings, if you leave your system locked for a while, your screen will eventually turn off. The setting can be customized but it’s triggered by system inactivity and not by the lock state of your desktop. If you want to turn off the screen on system lock, you can do so with a utility called SimpleMonitorOff.
Screen off on lock
Download and install SimpleMonitorOff. The app has no UI to speak of, it also doesn’t show any indication that it’s running and by extension, and it doesn’t have an off switch. Once it’s installed, it’s also automatically running. Lock your screen and within a few seconds, your screen will also turn off. The app works for both internal displays i.e., your laptop screen, and external displays i.e., monitors attached to your system.
The app also automatically adds itself to the start up apps so it will automatically run when you boot your system. Naturally, you may want a way to turn the app off, or at least stop it from starting when you boot to your system.
If you want to turn the app ‘off’, open Task Manager and on the Processes tab look for an entry called, ‘Intercepts the console being locked (e.g., with Win+L) and powers off the screen’. Select it, and click the End Task button.
To stop the app from running at startup, open the Task Manager and go to the Startup tab. Look for ‘Intercepts the console being locked (e.g., with Win+L) and powers off the screen’, and disable it. If you need to run the app again, you will have to find its EXE in the installation directory (C:\Program Files (x86)\SimpleMonitorOff) and run it from there. Running the app will not automatically enable it at startup again but you will have to quit it from the Task Manager whenever you want to stop it.
You can wake your screen any time by jiggling your mouse, or tapping a key, or tapping on your trackpad. The app can turn off as many displays as are attached to your system. We tested it out with two displays, one internal and one external, and it worked without a hitch.