Fix: BSOD Error code 0xc000021a in Windows 10

In this post, we discuss the probable reasons that cause the BSOD Error code 0xc000021a on Windows 10 PC along with a few working solutions. In general, the presence of incompatible third-party apps, pending Windows Update, or a corrupt hard drive may cause this error in the first place. Users often solve such issues by unplugging then re-plugging peripheral devices to the computer. 

In case of still stuck at the Blue screen, boot Windows into “safe mode with networking” and follow our six fixes. They are – Reset computer BIOS, Repair corrupt system files using SFC/DISM, and upgrade Windows 10 to the latest version. Hard disks usually last long, however, there’s no bad in checking its health performance running CHKDSK command. If none helps and the hard drive is all good, use system backups to restore your PC to an earlier fine state. Or, you may download the latest version of Windows 10 and fresh install it on your computer. Let’s explore the solutions in detail –

How to solve Error code 0xc000021a in Windows 10

To solve Error code 0xc000021a in Windows 10, use the following workarounds –

1. Remove all Peripheral devices then re-connect them back

The BSOD Error code 0xc000021a is most likely to occur owing to any corruption inside the secondary devices. So, before trying the software-related solutions, we suggest performing the below task –

Desktop Users

  • At first, shut down your PC (if on a blue screen, hold and press the Power button).
  • Detach all the Power cables connecting to the computer. 
  • Unplug all of the peripheral devices, clean dirt accumulated on the connecting wires. 
  • Open the CPU cabinet and remove the HDD wires, clean, and put them back to their positions. 
  • Connect the Mouse and Keyboard back to the system and hit the Power button. 
  • Windows should start normally. Now, try plugging each of the secondary devices one by one.

Note: Make sure to spend some time after connecting any device to the PC so as to find the corrupt hardware. 

Laptop Users

We don’t recommend opening the laptop casing as this might even wreck the whole operating system. You may follow the above guideline here as well, only if you have some expertise opening/closing the laptop casing. What you can do is cut off the power supply and remove the CMOS battery. Wait for a while then re-attach the battery at its position. Now, check whether this does solve the error 0xc000021a or not.

If not, follow the next set of solutions –

with Advanced Options

Since this a blue screen type error, you might not be able to get the login screen. Without accessing the PC’s settings you can’t do anything actually. However, you may boot into Safe Mode with Networking via the Advanced Options. Here’s how to proceed –

  • Keep restarting your PC for 2-3 times, and this will prompt Automatic Repair.

If you still don’t get the Automatic Repair window, use the below steps –

  • Use a bootable media (containing Windows 10 OS) and connect this to the computer.
  • Restart PC and keep on pressing the boot menu while Windows is loading.
  • This will let you enter the BIOS Mode. Here, select “Repair this PC” option.
  • Next, click Automatic Repair followed by Advanced Options.
  • On the “Choose an option” window, hit Troubleshoot.
  • Navigate to Advanced Options > Startup Settings
  • Here, press F5 or supported function key to enter Safe Mode with Networking.

After you boot inside the Safe Mode, try the below troubleshooting methods –

2. Repair corrupt system files using SFC Scan

The presence of corrupt or missing core Windows files may cause the 0xc000021a error in the first place. To fix them, you need to run the System File Checker tool using the below steps –

  • Click the Search icon and type Command Prompt
  • Right-click on the top result and select Run as administrator.
  • When the UAC window appears, hit YES.
  • Now, type sfc/scannow near the blinking cursor and hit Enter.


  • This will take a few minutes to scan and repair all system files, so wait accordingly. 
  • Once this is over, Reboot the computer.

3. Repair HDD corruption 

If there lies any corruption of the HDD, this may also result in BSOD error 0xc000021a. To solve this, you must use the DISM command-line. Here’s how to run this utility program –

  • Boot Windows into Safe Mode and start Command Prompt (with administrative privileges).
  • On the elevated console, execute the following code –

dism /image:c:\ /cleanup-image /revertpendingactions

Note: Usually, C:/ is the root drive. If not, replace “C:” with the appropriate disk letter.

  • Wait for a while as this takes a few minutes to complete the scanning and repairing process. 
  • Once over, come out of the command Prompt and Restart PC to implement the above changes. 

4. Replace corrupt files with backup using registry hive

Sometimes, certain registry hives get damaged and thus cause this Stop error 0xc000021a on Windows 10. If that’s the case, you need to replace the key-entry using registry backup. Again as you can’t access the file explorer, access the Windows Recovery Environment (WinRE) using below steps –

  • Insert the Windows Installation Media to the respective port and Restart PC.
  • While the OS is loading, press the suitable function key to boot into the BIOS settings.
  • Select the preferred settings like – language, time zone, and keyboard layout and hit Next.
  • On the succeeding screen, click Repair your computer available at the bottom left corner.
  • The Startup Options page will soon appear, navigate to the below path –

Troubleshoot > Advanced options > Startup Settings > Command Prompt

  • Select the root drive (usually C:) and execute the below code –

cd windows\system32\config 

Note: Accessing files or folders on the command prompt is quite easy if you know the initials. For example – 

  1. cd – stands for change directory and you may use this to open any further directory. 
  2. cd/ – take you to the root drive.
  3. dir – displays all of the folders available at the chosen location.
  4. ren – rename file
  • Change the SYSTEM file name using “ren SYSTEM SYSTEM.old” and “ren SECURITY SECURITY.old” for the SECURITY file.
  • Once you create the backup of each folder successfully, run the following codes –

cd RegBack



copy /Y SAM

copy /Y SYSTEM

Imp: Remember to note down the directory name where you have created a backup using registry hives.

  • Once over, type exit and press Enter to come out of the WinRE.
  • Remove the installation media and Reboot Windows so as to incorporate the above changes. 

5. Check HDD health

Often the BSOD error occurs owing to bad sectors on the hard drive. If you are still getting the 0xc000021a error, check the health performance of the hard disk using the following guideline –

  • Press Win and E shortcut to launch the File Explorer.
  • Right-click on the root drive i.e. (C:) and select Properties.
  • Next, go to the Tools tab and click the Check button right under “Error-checking.

BSOD Error code 0xc000021a

  • Wait for a while as this takes some time to finish the scanning process. 
  • Once over, check the report.

If all seems okay, run the CHKDSK command to perform a deep-scan and repair of the hard drive. Usually, this tool solves the errors that require a minor fix. Here is how to do –

  • Right-click on the Taskbar and select Task Manager.
  • Head over to the File menu and click Run new task.
  • Under the text area, type cmd (Admin).
  • Mark the box – “Create this task with administrative privileges” and press Enter.
  • Copy/paste the below code on the Windows console and hit Enter at the end.

chkdsk C: /f /r /x

BSOD Error code 0xc000021a

  • In case the error message “Check Disk Scan cannot proceed because the Volume is in use by another process” appears, type Y and hit Enter.
  • Restart your PC to let the system start performing the hard disk scan.

6. Use System Restore Point

Sometimes, the error code 0xc000021a appears just after installing the latest Windows Update. This might be possible only if you have installed the recent patch incorrectly. To solve this, you should either roll back Windows or use system restore points. Here’s how to restore PC to an earlier state –

  • Go to the start and type System Restore in the text box.
  • From the appeared list, click Create a restore point option.
  • Under the system protection tab, click the System Restore option.

System Restore

  • Here, opt either “Recommended restore” or “Choose a different restore point” and hit Next.

BSOD Error code 0xc000021a

Note: If you have chosen the second option, pick the backup, and click “Scan for affected programs“.

  • If all goes well, click Next again then Finish to begin restoring PC.

Performing this task should fix the BSOD error 0xc000021a. However, if you haven’t created any restore point in the past, clean install Windows 10.

7. Clean Install Windows 10 

If none of the above fixes work and the hard disk is alright, better download and install the fresh copy of Windows. Here’s how to do this –

  • Go to the official website and download Media Creation Tool 2004.
  • After the download completes, run the setup file.
  • Check the “Accept Terms and License” box, and hit Next.

Media Tool

  • Now, follow the on-screen instructions to complete the remaining steps.

Note: Make sure to check “Keep personal files only” radio button as you proceed further.

BSOD Error code 0xc000021a

  • Once the Windows 10 download completes, there appear two options – Create bootable media, create ISO file. Choose whichever suits you the most and apply the new OS to your computer.