In Windows NT, the state of the NUM LOCK key is specific to each user, and is off by default.

In tip 0023, we described the registry entries to enable NUM LOCK during logon.

To enable NUM LOCK during the CTRL+ALT+DELETE process, use Regedt32 to navigate to:

HKEY_USERS\.Default\Control Panel\Keyboard

Double click the InitialKeyboardIndicators value name, a type REG_SZ (string) value, and change the data value from the 0 to a 2.