Fixing the Blue Screen Error “0xc000021a” in Windows

Fixing the Blue Screen Error “0xc000021a” in Windows

/ Sed Galope

The 0xc000021a error is one of numerous Blue Screen of Death errors affecting all Windows operating system versions. STOP 0xC000021A, STATUS SYSTEM PROCESS TERMINATED, HALT: c000021a – Fatal System Error, and STOP c000021a are all representations for the same thing. It’s followed by a warning saying that Your PC has encountered a problem and has to restart in Windows 10.

Many customers have reported seeing this error message after upgrading to a newer version of Windows 10. When attempting to boot into Windows, it generally appears on the screen, making it difficult to resolve this BSOD error using only the BIOS and Advanced Startup mode tools.

As a result, you may be tempted to seek expert assistance. However, following the simple procedures below, you won’t need it to fix problems comparable to the Inaccessible Boot Device error.

What Causes the Microsoft Windows Blue Screen Error 0xc000021a

Most users who encounter the Windows error code 0xc000021a are upgrading or have just finished upgrading to a newer version of Windows. Users are unable to boot their computers due to the BSOD problem properly.

Windows Automatic Repair Tool

Windows 10
System Information
  • Your machine is currently running Windows 10
  • Restoro is compatible with your operating system.

Recommended: To repair Windows Errors, use this software package; Restoro System Repair. This repair tool has been proven to identify and fix these errors and other Windows problems with very high efficiency.

Download Now
Restoro System Repair
Norton Digicert
  • 100% safe as confirmed by Norton.
  • Only your system and hardware are evaluated.

There are several reasons for this problem. One of the most common reasons is that the devices in your peripherals or external devices plugged into the system are causing interference with starting the system. Additionally, several important system files needed to operate the system may be missing or corrupted, driven mainly by a failed Windows update or a virus infection.

Here are other causes of the Windows Error 0xc000021a and other critical system errors:

  • Misconfigured Windows registry entries
  • Corrupted files
  • Misconfigured driver signature enforcement feature settings
  • Important Windows files are missing from the Windows installation media
  • Incompatible software program installed in the system

Troubleshooting Methods to Fix the Stop Code 0xc000021a Error

The Windows OS error 0xc000021a prevents you from accessing the system. We will work on your computer in Safe Mode if you wish to go back into it without installing a fresh copy of Windows.

The safe mode of an operating system is a troubleshooting mode that can be used on a computer. The safe mode of an operating system is designed to help fix the majority of issues that can arise, if not all of them. It is also extensively used for uninstalling malicious software, particularly security programs.

Here’s how you can access Safe Mode:

  1. To access the Advanced boot options, press the power button under the Start Menu’s cog icon.
restart computer
  1. In the start submenu, hold the Shift key and press Restart.
  2. Wait for the system to boot into Windows Boot Menu. Click on Troubleshoot > Advanced Options > Startup Settings and tap on the Restart button.
startup settings
  1. Once the restart has finished, you will be greeted with the Startup Settings menu. In there, press 4 to enable safe mode. Alternatively, you can enable the safe mode with networking by pressing 5, and it’s generally better to go with option five here.
enable safemode
  1. Once your computer is in Safe Mode, we can now start performing troubleshooting steps.

First Method – Run the Windows Startup Repair

Startup repair, also known as Automatic Repair in older versions of Windows, is a built-in diagnostic tool in Microsoft Windows intended to promptly resolve the most frequent problems that keep your device from starting up in the operating system.

  1. Press the Shift key on your keyboard and simultaneously press the Power button.
shift power button
  1. You need to continue holding down the Shift key while waiting for the machine to power.
  2. Once the computer starts, you’ll find a screen with a few options. Click Troubleshoot.
  3. Next, click on Advanced options.
  4. In the Advanced options menu, choose Startup Repair.
startup repair
  1. Once the Startup Repair screen opens, choose an account. Be sure to use an account with Administrator access.
  2. After entering the password, click Continue. And wait for the process to complete.
  3. Reboot your PC and confirm if the stop code 0xc000021a has already been fixed.

Second Method – Scan Your System with the System File Checker

Windows SFC is a utility that checks for any damaged or missing files. The SFC checks the integrity of all protected system files and replaces outdated, corrupt, or changed ones with newer copies. This procedure may be used to repair corrupted update files causing the 0xc000021a error.

  1. While in Safe Mode, press “Windows,” press “R,” and type “cmd” in the run command line. Hold down the “ctrl and shift” keys together and hit enter to select Command Prompt. Enter the next window to grant administrator permissions and open the Command Prompt window.
  2. When the command prompt appears, type “sfc /scannow” and enter. SFC will now check for corrupted Windows update files. Wait for the SFC to complete the scan and restart the computer. Once done, run the Windows 10 Update tool to check if the issue has been fixed.
sfc scan
  1. Once the System File Checker scan is complete, boot Windows manually. Run the Windows update tool and check if this method finally fixed the Windows 10 error 0xc000021a.

Third Method – Uninstall the Last Application You Installed on Your Computer

Some software or apps can cause conflicts with your computer, resulting in Blue Screen errors like the 0xc000021a. We strongly advise you to uninstall the most recent application you downloaded and installed if you get this issue, as corrupt files may have come together with the program. We’ll eliminate Visual C ++ in the following examples, and the same procedures should be followed for any additional applications or programs.

  1. Hold down the Windows + R keys on your keyboard, type in “appwiz.cpl” on the run command line, and press “enter.”
  2. In the list of applications, look for the currently installed version of Visual C ++ and click uninstall.
uninstall application
  1. After uninstalling Visual C ++ Redistributable for Visual Studio from your computer, download the latest version of Visual C ++ Redistributable by clicking here.
  2. Make sure to download the latest setup file and the appropriate version for your computer and follow the on-screen instructions when installing the program.
  3. Restart your computer as usual and see if you can go to your regular Windows desktop and confirm if the Blue Screen error 0xc000021a has already been fixed.

Fourth Method – Disable Driver Signature Enforcement

Unsigned drivers are not allowed to run on Windows by default. So, if you just installed drivers from a source other than Microsoft, your operating system won’t start up because of Driver Signature Enforcement. As a result, the 0xc000021a error occurs.

  1. Access the Advanced boot options by pressing the power button under the Start Menu’s cog icon.
restart computer 1
  1. In the start submenu, hold the Shift key and press Restart.
  2. Wait for the system to boot into Windows Boot Menu. Click on Troubleshoot > Advanced Options > Startup Settings and tap on the Restart button.
startup settings 1
  1. Once the restart has finished, you will be greeted with the Startup Settings menu. In there, press number 7 to boot into the Windows OS with Disable Driver Signature Enforcement.
disable driver signature

Fifth Method – Perform a Clean Boot

If you can’t figure out what’s causing error 0xc000021a, you might want to try a clean boot. A third-party program or launching processes are usually at blame for the problem. Identifying the problem by disabling all startup applications and then re-enabling them is possible.

  1. Boot your computer into Safe Mode using the steps we listed in the method mentioned above.
  2. On your keyboard, press the Windows + R key.
  3. Once the run dialog box appears, type “msconfig” and click OK.
ms config
  1. In the System Configuration window, Locate the Services tab section and check the Hide all Microsoft services box.
  2. Click on the Disable all button and then select the Apply button.
disable non microsoft services
  1. Next, go to the Startup tab and select the Open task manager link.
  2. Choose startup programs one by one and then select the Disable button.
disable startup programs
  1. Restart your computer and check if the Windows error 0xc000021a has been fixed.

Sixth Method – Perform a System Restore

System Restore is a feature in Windows that lets users restore their system to an initial state, which can help recover from system failures or other issues. This method will remove all the files in your Windows system, including personal files. We strongly suggest performing this step if you already have a backup of your files.

  1. Download Media Creation Tool from the Microsoft website.
download media creation tool
  1. Run Media Creation Tool to create a Windows installation media (You can use a USB installation drive or CD/DVD).
  1. Boot the PC from the disc or USB drive.
  2. Next, configure the language, keyboard method, and time. Click Repair your computer.
repair computer
  1. Go to Choose an option. Choose Troubleshoot and Advanced options. Last, choose System Restore.
  2. Follow the wizard to finish a system restore.

Frequently Asked Questions

What does stop code 0xc000021a mean?

The 0xc000021a stop code indicates that a critical error has occurred in the Windows kernel. This is usually caused by corrupt system files. To fix this problem, you will need to use a Windows 10 repair tool to fix the corrupt files.

What causes Windows 10 Stop Code 0xC000021A?

The Windows 10 Stop Code 0xC000021A error is caused by a corrupt or missing boot configuration data (BCD) file. This file is responsible for storing information about the operating system’s boot process, and when it becomes corrupted or is missing, the system is unable to boot properly.

There are a number of ways that the BCD file can become corrupted, including errors during the Windows installation process, hardware failures, and software conflicts.

How do I fix Windows stop code registry error?

If you’re seeing a stop error code after upgrading Windows, it’s likely due to a corrupted registry. To fix this, you’ll need to run the Registry Repair tool. This will scan your registry and attempt to repair any corruptions that it finds.

What causes 0xC000021A?

The 0xC000021A error is caused by a failure in the user mode subsystem. This can happen when upgrading to a new version of Windows, or when an incomplete installation is present. In either case, the result is that the system cannot run properly.

Sed Galope
Meet the author

Sedfrey is an experienced writer and editor. He's also a PC hardware and gaming enthusiast. In his spare time, he enjoys reading about the latest innovations in the PC market and finding fixes to hardware and software errors.