You can add or reset PIN in Microsoft Account.
Get office setup here.
In case you’re experiencing difficulty utilizing your PIN to sign into Windows 10, have a go at resetting your PIN.
Take after these means:
On the sign-in screen, select I forgot my PIN below the PIN text box. If there are multiple accounts on the PC, choose the one you need to reset.
On the Enter your password screen, type the password for your Microsoft account, and then select Next.
On the Help us protect your info screen, choose to receive your security code either as a text or email message. If you select text, type the last four digits of your phone number, and then select Send Code.
When you get the code as a text or email message on a separate device, enter it on the Enter the code you received screen, and then select Next.
In the Set up a PIN dialog box, enter your new PIN and confirm it. Your new PIN is set.
For more details, visit : www.office.com/setup