Repair 0xc000021a Error in Windows 10, 8 and 7

Blue screens are nothing more than a problem for advanced Windows users. If an advanced Windows user says that I have never encountered a BSoD or STOP error, there is a 99% chance that he / she is lying. BSoD errors are not uncommon and can tell a lot of stories about the health and performance of your PC. One of these errors is 0xc000021a BSoD / STOP error.

If you are having trouble fixing the 0xc000021a problem, then you are in the right place, because we will help you fix it in no time.

You can find 5 ways to correct the error 0xc000021a on Windows 10, 8 and even Windows 7. But before we start with the solutions, let’s take a look at some more details about this error.

What is Blue Screen of Death error 0xc000021a?

The 0xC000021a error, as stated above, is a blue screen of death abbreviated as a BSoD error or STOP error that occurs when a Windows user mode subsystem .

This error is platform independent, that is, it occurs not only in the latest version of Windows 10 but also in Windows XP, Windows 7, Windows 8, Windows 8.1, and even Windows Vista.

Some of the required Windows user mode subsystems are:

  • Client Server-Runtime Subsystem (CSRSS)
  • WinLogon

These two mandatory files are compromised if:

  • There were corrupt system files on the computer.
  • There was a failed update.
  • Incomplete installation of a software program.

When even one of these two, responsible for the proper functioning of Windows, is compromised, Windows stops working and crashes on a blue screen with the following message:

STOP: c000021a {Fatal System Error} The Windows subsystem system process ended unexpectedly with a status of 0xc0000005. The system has been shut down.


There may be several unpredictable causes of error 0xc000021a HALT, but we list the main ones for you:

  • Misconfigured driver from software files
  • System entries / files are corrupted
  • System files do not match
  • Third-party software problems
  • Client Server Runtime Subsystem (CSRSS) corruption
  • WinLogon corruption
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How to repair the error 0xC000021A

Here is a list of complete steps that will take you to prevent the error 0xc000021a appear more:

Method 1: disable driver signing enforcement

This solution is one of the most operational solutions as reported by users as changing other boot entities to fix some issues with Windows such as disable driver signing enforcement . In simple worlds, blocking a security measure that restricts drivers that are not digitally signed or authorized to operate on Windows 10.

However, the freedom of Windows to use unsigned for the sake of some things to get it to work properly is what we live for. So, to keep using those drivers, follow the steps below:

  1. Press the Windows key and, while holding down the key Shift, select Restart from the Options of the power button .
  2. This will load your PC into the recovery mode .
  3. In the recovery window From the recovery menu options, select Solve problems .
  4. I touched Advanced Options followed by Startup settings .
  5. Finally choose Restart .
  6. Once the PC restarts, press the F7 key to choose Disable driver signing enforcement.
  7. The drive loads the installation media and checks for changes.

Method 2: run SFC

One of the above-mentioned problems if system files mismatch / corrupt. This registry entry corruption can cause serious problems, including reinstalling Windows 10 once. The corruption is mainly due to integrity issue or virus infection where some boot files get corrupted / damaged resulting in critical system error similar to installation error containing code 0xc000021a .

The list of ways to tackle this could go on and on, but to mitigate this and other similar issues, it’s best to use the System File Checker, a utility tool provided by Windows to check for system file corruption and mismatches and look for errors. . To implement the SFC tool, follow the steps below:

  1. Press Windows + X keys together and choose Command Prompt (Administrator) / Windows Powershell (Administrator) from the pop-up menu.
  2. In the command window, type “Sfc / scannow” as shown below and press Get in:
  3. Please wait while the tool checks system files for errors to automatically handle them.
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Hope this method has been solved 0xc000021a Stop error. If not, be sure to continue with a few more solutions detailed below.

Method 3: eject all peripheral devices

Although this seems to be an irrelevant solution at first, peripheral devices are considered to cause serious problems related to system files. The most logical reason is your stumbling block in the upload or update process.

As a result, this interaction can lead not only to blocking the blue screen of death, but also to other problems. But currently worried about the error code » 0xc000021a »That appears, ensure proper ejecting of all USB or DVD devices and other peripheral devices except mouse and keyboard. Also, disabling Pretty Everything will guarantee everything else in case one of these devices restricts the start of the Windows 10 installation process.

The solution to the problem is quite simple, but let’s not ignore it because it is simple. Could solve 0xc000021a Fatal error

Method 4 : disable windows services

Windows services must be restarted to reset the Windows update process. Restarting the Windows services resulted in the solution of this problem. Disabling Windows services is pretty easy:

  1. Press the Windows key + R together and in the text field write msconfig, so so much , press Enter (or click OK).
  2. In the window of configuration of system, switch to tab Services .
  3. If “Hide all Microsoft services” is unchecked, toggle.
  4. I touched Disable all and click the Apply button.
  5. Now switch to the tab Beginning next to Services one.
  6. Open Task Manager and deactivate all processes one after another and exit the Task Manager.
  7. I touched To accept to get out of the window Setting of the system .
  8. Finally, reboot your PC.

See if Windows started working properly without flashing the blue screen. If so, one of these services was interfering with the processes. You can debug and search for the same thing by disabling each service one at a time and eventually find the main culprit.

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Solution 5 – Rebuild BCD

If your computer cannot read the installation settings more than once, there is a good chance of boot sector deletion or corruption. Rebuilding boot configuration data abbreviated as BCD can help tackle boot sector corruption to repair bad sectors and thus load installation files without any hassle allowing users to begin the reinstallation process.

If you are not sure how to do it, please follow the steps below:

NOTE: – Make sure you have a Windows 10 installation disc or USB to perform the following operations.

  1. Insert the installation disk Windows 10 or USB.
  2. Restart your PC.
  3. Go to BIOS setup by pressing F10, F11, F12 at boot time and prioritize DVD / USB as the main boot device .
  4. After uploading the files, choose the obvious first is the idiom, then the date and hour correct , and keyboard input accordingly and tap «Next».
  5. In the next Windows menu, choose the option “Repair your computer” and consequently in the next window option Select problem solving .
  6. Finally select Advanced Options to start Windows Advanced option.
  7. Touch the symbol of the system by selecting the option of symbol of the system from the menu.
  8. Choose the ADMIN account and enter the password if prompted.
  9. In the command prompt window, enter the following commands and remember to press Enter after each of them:
    • bootrec / FixMbr
    • bootrec / FixBoot
    • bootrec / ScanOs
    • bootrec / RebuildBcd
  10. This will start the repair process and you will not face any error checking 0xC000021A: STATUS_SYSTEM_PROCESS_TERMINATE.


In the end, as always, I would suggest that if you are still having trouble with this one, leave your comment in the comment section below and you can always do a fresh install of Windows that fixes all your problems.

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