How to Fix Windows 10 stop code 0xc000021a

About the “0xc000021A” error

The evidence below on the error was formed through NeoSmart Technologies, based on the data composed and provided by our worldwide network of developers, engineers, and technicians or by other partner governments.

Description and Symptoms

The fault messages, alert messages, symptoms, and warnings listed below are all connected to this error.

Symptom 1: 0xc000021A error screen

The error 0xC000021A is a Blue Screen of Death or BSoD error (related: Blue Screen of Death guide) that can happen when the Windows user-mode subsystem has cooperated.


Windows user-mode subsystems comprise the Win Logon or Client Server Run-Time Subsystem (CSRSS). These two subsystems are obligatory to allow Windows to work.

If they are injured, Windows stops running and will display this error message. A message of fault that may show up on your screen generally:

STOP: c000021a {Fatal System Error}

The Windows Subsystem system process seems to have concluded brusquely, with the status 0xc0000005.

The system is now locked.

The causes of this error

This matter has been described to be the result of any one or more of the following:

1: Misconfigured software or driver

The most characteristic cause for this matter is an important element of software or system driver that is not operative correctly.

2: System registry is damaged

Another reason for this error could be an undependable registry on your system. It could be due to reading/writing disks, power outages, or bouts of viruses.

Fix 0xC000021A on Windows 8, 8.1 and 10

Solution 1: Clean the Boot

For a spotless boot, follow these steps. A Sparkling Boot can help you solve the 0xC000021A error thoroughly If it is occupied.

  • Boot into your system
  • Go to your desktop. Click Start
  • Press the window and R keys to launch the Run utility.
  • Enter msconfig
  • Press Enter
  • Click on to the General tab in the System Configuration window.
  • Click to start a precise startup
  • Uncheck the box Load items that are a startup
  • Go to the Services tab
  • Confirm the box to hide all Microsoft services
  • Click to disable all on the right side of the screen.
  • Go to the Startup tab
  • All services listed there are restricted by clicking right-clicking on each one, then clicking to disable
  • Restart the computer

If your system does not show the error 0xC000021A, then the service recognized in Startup could be the reason. To classify which service is answerable for this error, return to msconfig and allow each service individually. Then, restart your computer until the fault is displayed once more.

Solution 2: Remove drivers or software

A recently installed application or driver may cause this error. If solution 1 above was effective on your system, you must uninstall the program or driver.

You can also crisscross on the internet with the producer to find an up-to-date version or a Version that’s well-matched with the latest version of Windows 8 or 8.1

If you are inept at booting your PC, try booting in Safe Mode and then deinstall the wanted drivers or software:

  • Reboot your computer and press the F8 key just before you see the Windows 8 logo appears. If pressing the F8 key isn’t working, Try the F11 key.
  • Click Troubleshoot > Advanced Options > Startup Settings > Restart
  • Hold the F4 key to start the boot arrangement into Safe Mode.

If you own the inventive disc, you could use it to start Safe Mode.

  • Supplement the disc, and then reboot the system.
  • Use any keys to start the media
  • Click Repair your computer

  • Go to Troubleshoot and trailed by the Advanced Options. Click Troubleshoot, Advanced Options, Startup Settings, and Restart.
  • Press F4 to boot into Safe Mode.

Solution 3: Run the DISM command

You can boot Your Windows System into Safe Mode by using Command Prompt and then run the disk command following the steps in the below article:

  • Reboot your system
  • Use the F8 key on boot until the Windows 8 logo appears. If you’re not able to use the F8 key isn’t occupied, Try Shift, F8, or press the F11 button.
  • Select Troubleshoot
  • Choose Advanced Options
  • Choose Startup Settings
  • Click Restart
  • Use the key F6 to enter Safe Mode using Command Prompt.

  • When you see the Command Prompt seems, type this command and hit Enter: dism/image: C:/cleanup-image/revert any actions that are awaiting.
  • Substitute C with the name of the drive on which you have Windows 8/8.1/10 installation.
  • Other commands that you can run contain:



Move pending.xml pending.old

This will be operative when it is a pending.xml is complete.

If you cannot get into Safe Mode and are stuck, follow this to fix 0xC000021A using Simple Recovery Fundamentals. 

Solution 4: System Restore

If System Restore was permitted on your Windows 8/8.1/10, you could operate it to restore your computer to a prior date.

If you cannot use System Restore, go to fix 0xC000021A using the Easy Recovery Essentials.

  • Restart the computer
  • Press the F8 key or the F11 key
  • Select a keyboard layout when you are requested
  • Click Troubleshoot
  • Click Advanced Options
  • Click System Restore
  • Select the operating system.
  • System Restore will now open. Click Next
  • Choose a restore point and select Next
  • Make sure to click Close to prove the restore point.
  • Just click Yes on the warning message.
  • The procedure will end.

Solution 5: Driver Signature Disabled

If you turn off the driver Signature, Windows 8/8.1/10 will use drivers that aren’t specialized by Microsoft straight.

This technique can be operative when the mistake is caused by one of the drivers being loaded at the Startup.

  • Restart the computer
  • Press the F8 button. If the F8 keys don’t work, you can use the F11 key.
  • Choose to Troubleshoot > Advanced Options > Startup Settings
  • Click Restart
  • Press the F7 key to start Windows, and with the driver, signature implementation turned off

Solution 5: Reset

In Windows 8/8.1/10, You can retune your system. Before doing so, be conscious of the following:

  • Resets eliminate any personal data from your computer
  • If your computer is running Windows 8.1, Reset will reset your computer back to Windows 8. If you have finalized the Reset operation is accomplished, you will upgrade to Windows 8.1

Follow these steps:

  • Restart the computer
  • Press the F8 key or the F11 key
  • Select a keyboard layout, when you are asked
  • Click Troubleshoot
  • Click Reset your PC
  • Follow the instructions to finish the procedure.

I hope you find this helpful if you have any suggestions regarding the “0xc000021A” error, we would love to hear from you. 


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