9 Solutions to Fix Windows 10 Stop Code 0xc000021a

Why Do I Get the Windows 10 Install Error 0xc000021a?

Now, the question arises! What’s the reason behind getting a stop code 0xc000021a error? 

See, this could appear due to several reasons that you might not be able to identify, and primarily while updating your Windows 10, you might get this stop code error often. And, the cause behind getting this error could be the Winlogon.exe and Csrss.exe files. Some other viable reasons could be –  

  • Use of corrupted drivers
  • Unsupported installed applications or tools.
  • The intervention of external devices.

Why Does BSOD error 0xc000021a Appear?

If I explain explicitly, Winlogon.exe is accountable for handling the login and logout operations in Windows 10. And, when one installs new changes and tries running the system, then probably gets to see this error due to the mismatch of the supporting versions.

And the csrss.exe file is identical. It is responsible for the righteous coordination between the client and server. BSOD error may also occur due to malfunctioning of hardware or software installed or the overload upon the control processor unit.

To restore the BSOD stop the code 0xc000021a error issue from your system. You need to implement the following methods. So, follow me along to fix this unwanted issue: 

Method 1: Unplug External Devices

The minor issue that could be troubling you is the interference of your connected external devices. These external devices can affect your system’s function from working when introduced to new updates. Thus it is recommended to boot your Windows 10 machine only after detaching all the external devices.

And to know the point of menace. You can even try unplugging the devices one by one and checking which external devices of yours are the origin of the issue. If the error despairs, then that particular device was an issue to your system.

Method 2: Uninstall Recently Installed Software/Hardware

If you’ve installed any new software or hardware on your device, uninstall it instantly. Those newly installed software or hardware can cause you errors. How? Here’s how – when we install any software on our PC.

It shortly affects how our PC responds. And it may happen that the freshly inducted software in your system may not be endorsed by the updates of your windows, causing the BSOD code offense.

And to cure this, you need to uninstall the recently installed software downloaded by you. Uninstalling the software might help you in fixing the installation error caused by the windows.

Method 3: Boot Windows Without the Driver Signature Enforcement Feature

Driver Signature Enforcement feature helps protect the windows kernel by permitting only the signed or authorized user drivers to get in, which further retains the system security. And, this property of Driver Signature Enforcement, due to the lack of recognition of the user, rejects the system to install the drivers causing us unwanted errors.

To fix this issue. We need to disable Driver Signature Enforcement, which is a threat to our installation process. Now, let’s remove the problem from the roots. To do so, follow the following steps along – 

For this, you need to restart your Windows 10 device. As the restart begins, click the boot option button. You can search it for your system model name. Once you get your boot option key, continue pressing the key while the restart process is running. If you do it correctly, then the boot options screen will open up on your screen. Now, do the following steps:

  1. Enter the windows recovery environment.
Recovery environment  menu
  1. Look for the Troubleshoot option. And click enter.
  2. Now select Advanced options.
Troubleshoot advanced options startup
  1. There you’ll get to see Startup Settings.
  2. After advanced options startup settings, a restart button will show up on the screen. Click restart! 
Startup settings
  1. Once you did. Most probably, all the users will get to see Bitlocker on their screens. Just click enter and proceed.
  2. Now Bitlocker will ask you for a recovery key. To get your system’s recovery key, you need to visit this site – aka.ms/myrecoverykey.
  3. Once you complete all the authorization processes, you will get your Recovery key. You may get one or more recovery keys there.
  4. In the Bitlocker, Bitlocker will hint you for the correct recovery key. Enter the key and proceed. For entering the recovery key, you can use function keys or number keys. 
BitLocker recovery page
  1. Once you did it all. You’ll get to choose the settings you want to change. There you’ll find Disable driver signature enforcement, now select it, and proceed to return. 
Startup menu
  1. Now Restart the computer again.

Method 4: Fix Corrupted System Files via SFC

Here SFC notions System File Checker. It is a preloaded tool of windows that helps find, fix the system files and System restore. Before starting working with SFC, put your device in safe mode. If you didn’t do it, then you may get errors in using the SFC tool. So for this, obey the Microsoft Windows Safe Mode guide. 

Now, we are ready to fix the corrupted files on our device. 

Note: – To avoid errors! Make sure you open the command prompt in safe mode only.

Once you are in safe mode, follow the steps mentioned below to do the Sfc scan- 

  1. Render to the taskbar, search Command Prompt or cmd.
  2. Now, in the command prompt, type sfc /scannow
  3. Perform the following command and press enter.
  4. Now, the system file checker  will start scanning the damaged files and will fix all the files for you in seconds.
Running SFC scan in the command prompt

It must fix your issue if any infected files were the only obstruction in your system. If that too didn’t work, follow the next step.

Method 5: Run DISM Command

Here DISM notions Deployment Image Servicing and Management. DISM helps restore, prepare, modify the system images and Repair your computer. In the above steps, we have already fixed all the corrupted files from our device. 

Now, to make sure that infected files are not the issue. We’ll do one more check using the command prompt in the safe mode. By now, you must be knowing how to put your desktop into safe mode. If not, take the help of this guide – Microsoft Windows Safe Mode. So, to perform this test follow alongside:

Note: – To avoid errors! Make sure you open the command prompt in safe mode only.

  1. Search Command Prompt or cmd on the taskbar. And hit enter!
  2. In the command prompt, inscribe DISM /Online /Cleanup-image /ScanHealth, and proceed by pressing enter.
Running DISM scan in the command prompt
  1. Once the test is over, close the safe mode and restart your computer.
  2. If any damaged files are detected use DISM /Online /Cleanup-image /RestoreHealth command and press enter.

Method 6: Replace All Corrupted Registry Hive Files with Backups

We can understand Registry Hive Files as the storeroom of our system. It acts as a bin and collects the files from the user every time the new user gets devised and creates a separate source file for them. 

These files are stored and are unnoticed by the user that makes it difficult to maintain those files. With time the stored files may get corrupted, causing issues for us silently.

To fix this, we can replace all the damaged files with backup files. Right? So, let us fix this problem –

  1. For this, you again need to open the Troubleshoot from the boot menu.
  2. Now, select Advanced options and press enter.
  3. Once you click on it, you’ll get to see a bunch of options on your screen. In those, choose Startup Repair and press enter.
Startup repair

It will run a quick test for you and will fix all the issues. Once the scan is complete, it will tell you the status code for the scan. If things work fine, then try restarting your device.

Method 7: Reset BIOS

To fix the issue from the roots. You must now try resetting the BIOS. It may happen that some unusual behavioral changes in the Bios setup could be creating the BSOD 0xc000021a error. 

So to fix the issue, you should try resetting the BIOS setup. 

For this, obey the following steps:

There are three techniques in which you can Reset your BIOS setup-

  • Resetting directly from the BIOS setup (Preferred option):

Finding the troubleshooter in the boot menu is sometimes hectic work. As a substitute, you can do the following command:

  1. Access the windows settings of your device.
  2. Now, search for Recovery options in the settings search bar.
Searching Recovery options
  1. Once you reach recovery options, you’ll see a Restart now button
Windows recovery settings
  1. Once you click on it, you’ll be taken to the boot option menu settings, that you’re in the boot settings. From there, choose Troubleshoot.
  2. In Troubleshoot, select Advanced options.
UEFI firmware settings
  1. Now, in the advanced options, choose UEFI Firmware Settings. And then click restart.
  • Replacing CMOS battery (Hectic work):

To move with this, you need to power off your system. Now, remove all the connections from your system and open the frame of your device. And discharge the CMOS battery from the motherboard. Wait for a few minutes and insert the battery again. Now fit the chassis back and power on your system. Be cautious while taking out the batteries.

CMOS battery in the motherboard
  • Cleaning the jumper  (Hectic work):

You can locate the jumper very close to the CMOS battery, and to proceed… you need to follow the same procedure as in method-2. Plug out the jumper and place it back in its place. Now, try powering on your PC again.

If the issue was with your BIOS setup, then these steps will fix the problem for you. Not? Then kindly view the next steps.

Method 8: Recover or restore missing Data

At the beginning of the article, we discussed how winlogon.exe and csrss.exe version mismatch causes us the stop code 0xc000021a error. And what if our system lacks these important software files? Yeah, you’re right! We will get the same error. For this, you can use the third-party apps available. To recover the missing data for you.

To recover or restore the lost data, you can take the help of the trending restoration application tool MiniTool Power Data Recovery.

Once the application is ready to be used, follow the instructions below to recover the data files:

You will get two options to choose from: one restore from the PC and restore from the Hard Drive. It’s up to you from where you want to revive the lost files so you can choose accordingly. And, now hit the scan button to let the application collect the lost files for you. Once the scan is over, you can choose the files to revive and save to submit the changes. 

Method 9: Reinstall Windows Operating System

By now, we have done almost all the possible menace checks. Now the final thing you can do is reinstall your Windows system. And, to execute this, you’ll require an installation drive or the recovery environment disk available.

Now, follow the steps below to reinstall your PC safely:

  1. Insert the windows installation drive into your system.
  2. Open the Troubleshooter. If you get issues opening the troubleshooter option, go through the steps I have mentioned above.
  3. Now, Once you get to the troubleshooting options, choose to Reset my PC and hit enter.
Reset this PC
  1. Follow the reinstallation process as guided by the windows calmly. And your PC will be successfully reset to the initial state.
A Hand coming out of desktop screen to help fix the issues

I believe that this article would help you efficiently fix the error 0xc000021a. 

Frequently Asked Questions

What does 0xc000021a mean?

Getting an error code of 0xc000021a indicates that a problem has occurred while accessing the user sub-system mode, and the computer system was unable to handle it and wants you to take quick action to repair the issue.

How do I fix the 0xc000021a fatal error?

In short, you can do the following to fix the 0xc000021a issue:
Unplug all the external devices, and examine which device is preventing your PC from functioning
Uninstall freshly installed applications
Disable Driver Signature Enforcement
Run SFC scan
Run DISM ScanHealth and RestoreHealth
Replace All Registry Hive Files with Backup files
Reset BIOS settings
Restore absent data
Reinstall Windows os

What could cause a blue screen BSOD?

This issue may get raised due to the following problems: 
Installing new software
Malfunctioning of pre-installed software
Overheating of the CPU
Loose connections
Hard disk failure
As a whole, it is all associated with the functioning of the hardware and software running with your device.

Is the blue screen of death permanent?

No, It is just the event of the failure in running any particular command or the malfunction of any of the computer software. And can be remedied surely by following a few troubleshooting actions after investigating the origination of the problem. 
The blue screen is the warning for one to symbolize the unhandled issues and the seriousness of the threat may vary depending on the bug detected.

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