Ensure NumLock is ON via PowerShell

Set-NumLockOn.ps1

Add-Type -TypeDefinition @"
  using System;
  using System.Runtime.InteropServices;

  public static class NumLock {
    [DllImport("user32.dll", CharSet = CharSet.Auto, ExactSpelling = true, CallingConvention = CallingConvention.Winapi)]
    public static extern short GetKeyState(int keyCode);

    [DllImport("user32.dll", EntryPoint = "keybd_event", CharSet = CharSet.Auto, ExactSpelling = true, CallingConvention = CallingConvention.Winapi)]
    public static extern void keybd_event(byte bVk, byte bScan, int dwFlags, int dwExtraInfo);

    public const byte VK_NUMLOCK = 0x90;
    public const int KEYEVENTF_EXTENDEDKEY = 0x1;
    public const int KEYEVENTF_KEYUP = 0x2;

    public static void EnsureNumLockIsOn() {
      short numLockState = GetKeyState(VK_NUMLOCK);
      bool numLockIsOn = (numLockState & 0x1) == 0x1;

      if (!numLockIsOn) {
        keybd_event(VK_NUMLOCK, 0x45, KEYEVENTF_EXTENDEDKEY, 0);
        keybd_event(VK_NUMLOCK, 0x45, KEYEVENTF_EXTENDEDKEY | KEYEVENTF_KEYUP, 0);
      }
    }
  }
"@

[NumLock]::EnsureNumLockIsOn()