Microsoft has released another Knowledge Based (KB 154529) article. This Fix it enables the NUM LOCK key for the logon scree. This is only applies to Windows XP, Windows 2000.
The status of the NUM LOCK key is specific for each user, and NUM LOCK 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.
To enable NUM LOCK before a user logs on, follow these steps:
To fix this problem automatically, click the Fix this problem link. Next, click Run in the File Download dialog box, and then follow the steps in this wizard.