The status of the NUM LOCK key is specific for each user, and it is disabled by default. If you want the NUM LOCK key enabled for use before a user presses CTRL+ALT+DEL to log on, you must use Registry Editor to change the default behavior.
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WARNING: If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.

To enable NUM LOCK before a user logs on, use the steps below.

1. Run Registry Editor (Regedt32.exe).
2. Navigate to HKEY_USERS\.Default\Control Panel\Keyboard.
3. Change the value for InitialKeyboardIndicators from 0 to 2.