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How to Fix Windows A1B2C3 Challenge Phrase

by Gaurav Bidasaria
How to Fix Windows A1B2C3 Challenge Phrase

Microsoft has recently implemented a challenge phrase security feature with the objective to reduce brute-force login attempts on Windows 10 and 11 computers. What it does is display the A1B2C3 error and ask the user to enter the challenge phrase which is literally A1B2C3. What’s weird is that users are getting confronted with the A1B2C3 challenge phrase even after they have entered the correct pin. Here’s how to fix A1B2C3 challenge phrase on Windows 10/11 computers.

Using Password

The first thing you need to do is sign in to your Windows computer. Otherwise, how will you troubleshoot the A1B2C3 challenge phrase problem? If you have set up PIN as your sign-in method on Windows, then you also have a password option. Windows don’t allow setting up PIN without a password.

windows sign in options screen

Under the box where you would normally enter your PIN, look for the Sign-in Options button. Click on that to reveal more ways to sign in. You should find either password or fingerprint or face unlock here. Use one that you have access to and sign in to your Windows account.

Change PIN and Password

Several users found that changing the pin and password of their Windows 10/11 account resolved the A1B2C3 challenge phrase issue. To change password or pin:

1. Press Windows + I to open Settings. Select Accounts from the sidebar and click on Sign-in options.

windows sign in options

2. Select PIN (Windows Hello) and click on Change PIN button.

change sign in pin of windows user account

3. In the pop-up that follows, enter your old pin and then your new pin twice. Click on OK to save.

changing Windows Hello PIN in windows

Follow on-screen from here on and you are done.

Pro Tip: 4 Ways to Use iPhone as Second Monitor With Windows and macOS

Remove NGC Folder Content

Windows saves your login information in the NGC folder. Needless to say, if the folder is corrupt, has files with bugs, or lacks correct permissions, you will face sign-in errors like challenge phrase A1B2C3 error.

1. Sign in to your Windows administrator account.

2. Navigate to the folder structure below.


Note: The folder AppData is hidden by default for safety reasons. You need to unhide it. To do that, in File Explorer, click on View > Show > Hidden items.

how to view hidden folders in windows file explorer

3. Right-click on the Ngc folder and select Properties.

NGC folder properties in windows file explorer

4. Under the Security tab, click on Advanced button.

windows NGC folder security

5. Click on Change link next to the Owner section.

change ngc folder owner in microsoft file explorer

6. Type administrators (no space before or after) in the pop-up that follows in the given field and click on Check Names button.

check admin name in windows file explorer

7. It will detect the username automatically. Click on OK to save changes.

8. You should now be able to enter the Ngc folder. Double-click to open the folder and delete all files saved within.

9. Now you need to set up Windows Hello or PIN, face unlock, or fingerprint as you wish.

What If I Forgot the Password

That’s a separate issue and beyond the scope of this article. However, on the sign-in screen, you should I forgot my PIN or Reset password option. If yes, use that and follow on-screen instructions to change the password or PIN on your Windows computer and regain access.

Bonus Tip: Use Fingerprint or FaceUnlock

If your Windows computer has a webcam and/or fingerprint reader, we recommend you set it up. That would make it so much easier to sign in to your Windows computer. No need to remember and enter a pin or password now.

Challenging Times

We don’t recommend you remove your password/PIN completely just because you are seeing the A1B2C3 challenge phrase screen as it leaves your computer vulnerable. Anyone with physical access to your Windows 11 and 11 PCs can steal data or change settings, for example. You don’t want that. Windows Hello was designed to protect your privacy and offer security. Instead, set up multiple sign-in methods like password, PIN, fingerprint or face unlock so if one doesn’t work, you have a backup.

Now that you have entered your computer, it’s time to optimize it to get the max out of it.

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