PS: Lock Computer And Turn Off Monitors

less than 1 minute read


There is a pretty known way to lock your computer using the user32.dll, but what isn’t as easy to find is a way to turn off your monitors as well. Sometimes, like when I’m done for the day on my home computer, I want to lock it AND turn off my screens.

To Resolve:

  1. There are two main options, one is a Powershell Script and the other is using NirCmd.exe. Both are free and pretty easy to configure.

1a. The Powershell script:

Add-Type -TypeDefinition '
using System;
using System.Runtime.InteropServices;
namespace Utilities {
   public static class Display
      [DllImport("user32.dll", CharSet = CharSet.Auto)]
      private static extern IntPtr SendMessage(
         IntPtr hWnd,
         UInt32 Msg,
         IntPtr wParam,
         IntPtr lParam
      public static void PowerOff ()
            (IntPtr)0xffff, // HWND_BROADCAST
            0x0112,         // WM_SYSCOMMAND
            (IntPtr)0xf170, // SC_MONITORPOWER
            (IntPtr)0x0002  // POWER_OFF
"%windir%\system32\rundll32.exe user32.dll,LockWorkStation"

1b. The nircmd.exe way: Create shortcut, edit target:

# Wait two seconds and turn off the computer monitor.

“C:\path\to\nircmd.exe” cmdwait 2000 monitor off

# Optional: Assign hotkey, change icon to lock, place in taskbar