Number Lock

Edit the following registry key

HKEY_CURRENT_USER\Control Panel\Keyboard

InitialKeyboardIndicators: REG_SZ: NUMBER

Default: 0

Set this value to 2 to enable the num lock to be on.

Also look in the BIOS of the computer and see if there is a setting like this for the PC.

I got this answer from technet article Q154529.

To enable NUM LOCK before a user logs on, use the steps below.

WARNING: Using Registry Editor incorrectly can cause serious, system-wide
problems that may require you to reinstall Windows NT tocorrect them.
Microsoft cannot guarantee that any problems resulting from the use of
Registry Editor can be solved. Use this tool at your own risk.

1. Run Registry Editor(Regedt32.exe).

2. Navigate to HKEY_USERS\.Default\Control Panel\Keyboard.

3. Change the value for InitialKeyboardIndicators from 0 to 2.

HKEY_CURRENT_USER\ControlPanel\Keyboard and look for the value InitialKeyboardIndicators. By default, this value is set to "0", which causes NumLock to be turned off after logon. A value of "1" disables NumLock. A value of "2" causes NumLock to be turned on after logon.

i wrote a policy-template (adm-file) too. here it is:

CLASS USER

CATEGORY !!Numlock On at Startup
KEYNAME "Control Panel\Keyboard"

POLICY !!Numlock On at Startup
VALUENAME "InitialKeyboardIndicators"
VALUEON NUMERIC 2 VALUEOFF NUMERIC 1
END POLICY
END CATEGORY ;

[strings]
Numlock On at Startup="Enable NUM LOCK before a user logs on"

good luck