Is there a program that will prevent changing the numlock state? [closed]

"AutoHotKey?

SetNumlockState, AlwaysOn

would lock the numlock.

edit: You may also consider

Numlock::MsgBox, [your message here]

or

numlock::shift

to map it to shift - allowing you to hold down the key and use it as arrow keys, or not hold the key, and use it for numbers."

"In the registry, open HKEY_CURRENT_USER\Control Panel\Keyboard.

The entry InitialKeyboardIndicators can have the following values:

0 = NumLock is turned OFF after the logon.
1 = Disable NumLock.
2 = Numlock is turned ON after the logon.

EDIT

If I understand your dilemma correctly, you like one NumLock setting and your boss likes another. So why don't you create another user account for your boss? You can also use a screen-saver with your password, to force him to logon in order to use the computer. I believe that's a better solution than monkeying with the registry.

Regarding the registry key, there are actually two of those. Here's how it works:

After boot and before login, Windows reads
HKEY_USERS\.DEFAULT\Control Panel\Keyboard\InitialKeyboardIndicators
and sets it up as default. After Logon, Windows Applies the setting from
HKEY_CURRENT_USER\Control Panel\Keyboard\InitialKeyboardIndicators (0=Off, 2=On).
This setting is stored independently inside each user profile, and the state from the Windows Session is saved at logoff. This means if you turn your NumLock on, a value of 2 is written at logoff, and NumLock will be toggled on at next login."