I like my num lock to be on by default when I enter Windows. On my work laptop it for some reason never was. Here’s how to fix it.

1. Open RegEdit (Start, run, type regedit, hit enter)
2. Select the top node, Computer
3. Search for InitialKeyboardIndicators (Edit, Find or (Ctrl+F))
4. If what you find has a numeric value, change it to one of the values below:
   • 0 – Turn all indicators Off (NumLock, CapsLock, ScrollLock)
   • 1 – Turn CapsLock On
   • 2 – Turn NumLock On
   • 3 – Turn CapsLock and NumLock On
   • 4 – Turn ScrollLock On
   • 5 – Turn CapsLock and ScrollLock On
   • 6 – Turn NumLock and ScrollLock On
   • 7 – Turn all indicators On (NumLock, CapsLock, ScrollLock)
5. Keep searching (F3) until you’ve found all the numeric ones and changed them to the same value

Below are the different values you can set. I set mine to 2. Most of them already were, but some were some large number of several digits. Looked to be close to max int or something, so maybe a bug… either way, after rebooting my num lock key was now on 🙂

Source: Microsoft Answers