Ensure You Aren't Entering the Incorrect PIN
Sign-In Using Alternative Methods
Delete the Ngc Folder in Windows
Rule Out User Account Specific Issues
Tweak PIN Sign-In Settings in Group Policy Editor
Update or Downgrade Your OS
Turn Off Your Antivirus and Run a Malware Scan
Run an SFC Scan
When removing malware, make sure it hasn't harmed any important Windows files that are causing the current problem. Apply an SFC scan to automatically detect and replace damaged files with cached copies.
If SFC does not resolve the problem, revert to the previous system restore point where the PIN worked. Note, that this is only possible if you have created a restore point.
Ensure You Aren't Entering the Incorrect PIN Sign-In Using Alternative Methods Delete the Ngc Folder in Windows Rule Out User Account Specific Issues Tweak PIN Sign-In Settings in Group Policy Editor Update or Downgrade Your OS Turn Off Your Antivirus and Run a Malware Scan Run an SFC Scan