Hello, thank you for reaching out to Microsoft Q&A.
If you are unable to sign in to your computer, could you please check if you can reset your PIN from Safe Mode?
To boot your PC in safe mode,
- Start your device and wait for the Windows logo (or the manufacturer's logo) to appear.
- As soon as the Windows logo appears, press and hold the power button until the device shuts down.
- Turn your device on again and repeat step 2.
- Turn your device on a third time. Windows should display the Automatic Repair screen.
You can then select Troubleshoot > Advanced Options > Startup Settings > Restart.
Press F4 to boot your PC in safe mode.
Go to Start > Settings > Accounts > Sign in options > PIN > Change PIN.
Set up a new PIN and restart your PC.
Let me know if you still need more help.