Attivato.
Su diversi portatili che mi son passati per le mani è però disattivato.
Ho risolto con:
Navigate to registry key HKEY_USERS\Default\Control Panel\Keyboard
Right click on the “InitialKeyboardIndicators”, select Modify and change Value data to 2.
Exit Registry.
Note: If you see the default value data as 2147483648; that is fine too and is the default on most installations.

I hope you find this helpful.

UPDATE: Please also read Ken’s comment below. A value of 2147483650 helped him.
Nell'ultima build insider:
Making pin login easier: Ever tried to enter your pin, only to discover the numbers you’ve been typing are nowhere to be seen because Num Lock was off? We’re happy to announce that that will no longer happen! With this build, regardless of your Num Lock state, numbers will be input if you’re typing into the pin password field. Let us know what you think!