How to Fix Windows A1B2C3 Challenge Phrase

ByJim Miller

Microsoft has recently introduced a new security feature in Windows 10 and 11 to combat brute-force login attempts. This feature displays the A1B2C3 error and asks users to enter a challenge phrase, which is literally “A1B2C3.” However, some users are encountering the A1B2C3 challenge phrase even after entering the correct PIN. In this article, we will discuss how to fix the A1B2C3 challenge phrase issue on Windows 10/11 computers.

Sign-In Using Password

To troubleshoot the A1B2C3 challenge phrase problem, the first step is to sign in to your Windows computer. If you have set up a PIN as your sign-in method, you also have a password option. Windows does not allow setting up a PIN without a password.

Under the box where you would normally enter your PIN, look for the “Sign-in Options” button. Click on it to reveal more sign-in methods, such as password, fingerprint, or face unlock. Choose the one you have access to and sign in to your Windows account.

Change PIN and Password

Many users have found that changing the PIN and password of their Windows 10/11 account resolves the A1B2C3 challenge phrase issue. Follow these steps to change your PIN or password:

  1. Press Windows + I to open Settings. Select “Accounts” from the sidebar and click on “Sign-in options.”
  2. Select “PIN (Windows Hello)” and click on the “Change PIN” button.
  3. In the pop-up that appears, enter your old PIN and then your new PIN twice. Click “OK” to save the changes.

Follow the on-screen instructions to complete the process.

Remove NGC Folder Content

Windows stores your login information in the NGC folder. If this folder is corrupt, contains files with bugs, or lacks correct permissions, you may encounter sign-in errors like the A1B2C3 challenge phrase error. To fix this issue:

  1. Sign in to your Windows administrator account.
  2. Navigate to the following folder: C:WindowsServiceProfilesLocalServiceAppDataLocalMicrosoft (Note: The AppData folder is hidden by default. You need to unhide it by clicking on View > Show > Hidden items in File Explorer.)
  3. Right-click on the Ngc folder and select “Properties.”
  4. Under the Security tab, click on the “Advanced” button.
  5. Click on the “Change” link next to the Owner section.
  6. Type “administrators” (without spaces) in the pop-up window and click on “Check Names.”
  7. Once the username is detected, click “OK” to save the changes.
  8. Double-click on the Ngc folder to open it and delete all the files saved within.
  9. Set up Windows Hello or choose a new sign-in method as desired.

What If I Forgot the Password

If you have forgotten your password, you can use the “I forgot my PIN” or “Reset password” option on the sign-in screen. Follow the on-screen instructions to change the password or PIN on your Windows computer and regain access.

Bonus Tip: Use Fingerprint or Face Unlock

If your Windows computer has a webcam and/or fingerprint reader, we recommend setting it up. This will make it easier to sign in without remembering and entering a PIN or password.

Challenging Times

While encountering the A1B2C3 challenge phrase may be frustrating, we do not recommend removing your password or PIN completely. This leaves your computer vulnerable to unauthorized access. Instead, set up multiple sign-in methods like password, PIN, fingerprint, or face unlock. This way, if one method fails, you have backups in place to ensure the security and privacy of your Windows 10/11 computer.

Now that you have resolved the A1B2C3 challenge phrase issue, you can optimize your Windows computer to get the most out of it.