SimpleMonitorOff is a freeware Windows application which powers off your screen (or screens) when you lock your computer.
When you lock your computer (eg. with Win+L) then ordinarily your screen(s) will not immediately go to sleep. SimpleMonitorOff detects that you have locked your computer, and requests that the screen(s) be powered down. Shortly afterwards your screen(s) will do so (ie. go into standby mode).
When you move your mouse or hit a key, they will wake again to let you unlock the computer.
If you (or your cat) did that by accident, then after a little while your screen(s) will power down again.
Note: Unlike many similar applications, SimpleMonitorOff does not require any additional hotkeys, mouse clicks, or shortcuts – it responds to events sent by Windows itself, so will respond to you locking your computer however you choose to do it, rather than expecting a specific hotkey combination or shortcut.
SimpleMonitorOff is compatible with Windows 7 onwards. It has been specifically tested with Windows 7, Windows 8.1, and Windows 10, but should work on all compatible versions of Windows.
Currently it is shipped as a 32-bit application for maximum compatibility.
It has been tested with Standard (a.k.a. Limited) User accounts, and shown not to need administrator privileges to run (apart from upon initial installation).
Like most applications, you need administrator privileges to install or uninstall SimpleMonitorOff. Other than that, administrator privileges are not required.
Once installed, there is no user interface. It will autorun on system startup and consume minimal resources, just listening for the Windows notifications that tell it whether or not you have unlocked your computer, and whether or not the power status of your screen(s) has changed.
To disable it, simply terminate SimpleMonitorOff.exe using Task Manager, or uninstall it.