Windows Stop Code 0xc000021a [Fixed by Experts]

Summary: A new BSOD error with a bug check value 0xc000021a has captured our attention after users start posting queries about this error. In this blog, read why this blue screen error occurs and how to fix it without losing data.

Table of Contents:

  1. What is Stop Code 0xc000021a & how it occurs?
  2. How to fix 0xc000021a error code?

Several Windows users’ have posted queries on Reddit and Microsoft forum related to 0xc000021a stop code. Some said that this error code occurred after a Windows Update installation, while others stated that it appeared out of nowhere while working on their system. And, when they restarted their PC, it got stuck at a booting loop. Users posted their queries with different names for the error such as,

Refer to the following users’ queries from Reddit and Microsoft:

My Windows 10 Pro PC stopped booting two days ago. It goes into the repair/diagnosing loop and has an error code 0xc000021a. I went through all the advanced options to repair it and to disable the blue screen. I am aware of some troubleshooting, which I have tried, but cannot fix. This error has got me worried. Could anyone tell how to fix it?

Well, circumstances could be different, but the problem remains the same. So, how would you fix it?

Worry not! You can fix it by attempting the methods shared in this blog. However, before that, let’s first understand this error and its causes.

What is Stop Code 0xc000021a & how it occurs?

The stop code 0xc000021a represents the WINLOGON_FATAL_ERROR, which occurs when a user-mode subsystem, such as WinLogon or Client Server Run-Time Subsystem (CSRSS), is compromised. It additionally means that security can’t be guaranteed for your system due to this error. And in turn, the Windows Operating System (OS) switches to the kernel-mode, showing a blue screen.

Sometimes, when you restore your hard disk from a backup, the system files can be corrupted or faulty and may cause this error on your system. Other causes behind the 0xc000021a error may include a corrupted hard drive, faulty device drivers, incompatible software/app installed, and problematic Windows update.

Irrespective of the reasons, you can fix it. We’ve collated the best possible methods to help you get rid of such blue screen errors. You can attempt the below-discussed methods by following them step-by-step.

Caution: Some of the given methods may cause data loss. Therefore, we suggest you take backup of your system data and then troubleshoot the problem.

How to fix the 0xc000021a error code?

  1. Run SFC Tool
  2. Run Windows Defender Antivirus Tool
  3. Update/Uninstall Device Driver
  4. Uninstall Problematic Windows Update
  5. Run CHKDSK Command
  6. Uninstall Incompatible Software/Application
  7. Perform System Restore

Consider booting your PC into safe mode to prevent any element from causing trouble while you’re trying to fix a BSOD error.

To enter Safe Mode, follow the given steps:

  1. Restart your system; as soon as you see the Windows logo on the screen, reboot it again and repeat this step thrice.
  2. After that, you’d reach the Automatic Repair environment.
  3. There, click ‘Advanced options’, leading you to the ‘Choose an option’ screen.
  4. There, click Troubleshoot > Advanced options > Startup Settings > Restart.
  5. Once your system gets restarted, click F4 to enable Safe Boot.

Now that you’re booted into safe mode, you can proceed with performing troubleshooting methods.

Method 1: Run SFC Utility

DISM.exe /Online /Cleanup-image /Restorehealth

Method 2: Run Windows Defender Antivirus Tool

Method 3: Update/Uninstall Device Driver

If you already have the latest driver, try uninstalling it and then re-installing it with the compatible one.

Choose Uninstall device.

Method 4: Uninstall Problematic Windows Update

Method 5: Run CHKDSK Command

Caution: While performing the CHKSK command, you may end up losing data as it doesn’t read and store data from the bad sectors of the hard drive. We recommend you take backup of your system or recover your data with a powerful data recovery software.

To run the CHKDSK command, follow the given steps:

Also Read: Running CHKDSK May Affect Your SSD and Cause Blue Screen

Method 6: Uninstall Incompatible Software/Application

Method 7: Perform System Restore

If the above methods don’t fix the stop code 0xc000021a, you can try performing System Restore. However, it brings the system to default or chosen restore point.

Therefore, backup your system data or in case of data loss, restore it using a reliable data recovery software, such as Stellar Data Recovery Professional. It is a DIY tool that lets you recover data from formatted, corrupted, unbootable, crashed, or BSOD-affected Windows systems and storage devices, such as HDDs, SSDs, USB drives, etc.

Once you’re done with backing up or recovering your data, proceed with the following steps:

Encountering a blue screen error with a stop code 0xc000021a error randomly, could be quite annoying. To tackle such BSOD errors, you can try out the DIY methods given in this blog, including running SFC utility, CHKDSK command, Windows Defender program, uninstalling a problematic Windows update or software, or performing System Restore. But be aware that methods such as running CHKDSK and System Restore may cause data loss. So, take a backup of your system data before performing these methods or restore it using reliable data recovery software.

If you’ve encountered any other BSOD error on your Windows PC, let us know in the comment section below!

Also Read: How to Fix the Error Code 0xc0000225?

Related Post

Stellar Data Recovery

Trial Download is for Desktop or Laptop. Put your email id to receive the download link




Exit mobile version