To enable NUM LOCK before a user logs on, follow these steps. This will keep NUMLOCK enabled even after a user logs off or restarts the machine.
1. Open Regedit
2. If you want to make the change on a remote computer, go to File > Connect Network Registry. Type in the GB number and hit Enter
3. Navigate to HKEY_USERS\.Default\Control Panel\Keyboard
4. Change the value for InitialKeyboardIndicators from 0 to 2.
5. Hit Ctrl-F and look for all entries of 'InitialKeyboardIndicators' - there should be five. Change their values to 2.