It is good that NumLock is switched off in the logon screen!
I felt I need to announce my opinion regarding this to the entire world! Like many others, perhaps you have noticed that during logon to Windows XP, Windows Server 2003, Windows Vista and Windows Server 2008, NumLock key on your keyboard is inactive by default.
I for one, consider it a good security measure. NumLock being off reminds me that I should not use numeric keypad to enter the numbers in my password. Using the default number row instead of keypad would deny remarkable others (not be mistaken with "significant others") the opportunity to easily find out whether you use numbers is your password, where exactly you use password and how many times numbers occur in the entire password.
So, if you plan to ask me how to have NumLock active in the logon screen, then, with all due respect, I’m afraid I don’t know. (You know the meaning and usage scenarios of "with all due respect", don’t you?)