Because of XP's multi-user functionality, NumLock does not toggle on by default (system-wide), even if you have it set in your PC's BIOS.
Here is a hack the Windows Registry to change this behavior.
Standard Warnings About Careful Registy Hacking Apply!
To enable NumLock through the Registry:
1. Open Windows Registry Editor - START > RUN, type in "REGEDIT" (w/o the quotes). 2. Navigate to HKEY_USERS\.Default\Control Panel\Keyboard. 3. Change the value for InitialKeyboardIndicators from 0 to 2.
Or, if you have more than one user on your system and one or more don't want NumLock on, run a script at logon to turn NumLock on, This allows you to only attach the script to specific users. To enable NumLock using a script, see this MS Knowledgebase article for complete instructions: