To enable Numlock before users log in
You'll want to change this key
[HKEY_USERS\.DEFAULT\Control Panel\Keyboard]
Set InitialKeyboardIndicators = 2
If you want to enable it for the user (WinXP is suppose to retain the last
state of this button every time you log off)....
To force it on..
[HKEY_CURRENT_USER\Control Panel\Keyboard]
Set InitialKeyboardIndicators = 2
To enable numlock during bootup, you'll need to set the numlock enabled
option in your bios