How To Fix Windows 10 Update Error 0xc000021a [Solved]

If you are Windows 10 users and facing “Windows 10 KB4561608 update Error code 0xc000021a” on your devices, then you are in right place. Here, we are discussing about “Update Error code 0xc000021a” and providing some recommended solution to fix this issue.

Error code 0xc000021a” is categorized as Windows update error that appears with BSoD (Blue Screen of Death). Many users have reported about the Windows 10 update Error 0xc000021a on various online platforms including Microsoft official online forums and asked for the solution. Users explained that they are receiving this error while trying to install Windows 10 security update KB4561608 on their PCs/Laptops. Let’s take have a look at error popup message.


The STATUS_SYSTEM_PROCESS_TERMINATED bug check has the value of 0xc000021a. This means that an error has occurred in crucial user-mode subsystem”


“Cumulative update for Windows 10 version 1903 and higher (KB4561608) – Error 0xc000021a”

There is a various reason that causes Windows 10 security Update KB4561608 fails to install like poor internet connection refuse download the update files from Microsoft server, corrupted important System files, corrupted drivers or other software, missing or corrupted Windows update, malfunctioning in your System registry settings and other many other problems. So, you should make sure that your System is stable. If you sure, you can download/install the Windows 10 Update KB4561608 easily. To fix Windows 10 Update KB4561608 error code 0xc000021a, you can follow the instructions given below.

[Tips & Tricks] How to fix Windows 10 Update KB4561608 Error code 0xc000021a?

Procedure 1: Run Windows Update Troubleshooter

Step 1: Press “Windows + I” key together from keyboard to open “Settings” App

Step 2: Click on “Update & Security > Troubleshoot”

Step 3: Select “Windows Update” option on right-hand side and click on “Run the troubleshooter” button

Step 4: Wait for the completion. This process will detect the problems that prevent Windows update install and repair the System automatically.

Step 5: Once done, restart your computer and please check if error is resolved.

You may also read: How To Download Windows 10 Build 19041.329?

Procedure 2: Clear Windows update download folder

Step 1: Press “Windows + X” key together from keyboard and select “Command Prompt as Administrator”

Step 2: In the opened “Command Prompt” window, type the following command one- by-one and execute each command by pressing “Enter” key

  • net stop bits
  • net stop wuauserv
  • net stop appidsvc
  • net stop cryptsvc

Step 3: Now, open “C:\Windows\SoftwareDistribution\Download” folder and delete everything in the folder. So that Windows download the fresh update files next time. To do this, press “CTRL + A” to select everything and press “Delete” button from keyboard

Step 4: Open Command Prompt again using ‘Step 1’ and type the following commands one-by-one and press “Enter” key to execute them

  • net start bits
  • net start wuauserv
  • net start appidsvc
  • net start cryptsvc

Step 5: Finally, close Command Prompt window and restart your computer. Once done, please check if Error code 0xc000021a is resolved.

Procedure 3: Run SFC and DISM tools

To run SFC tool, follow the steps below

Step 1: Click on “Start” button and type “CMD” in Windows Search

Step 2: Right-click on Command Prompt from searched results and click on “Run as Administrator”

Step 3: In the opened “Command Prompt” window, type “sfc/scannow” command and hit “Enter” key

Step 4: This process will scan and restore missing System files. Once done, close Command Prompt and restarts your PCs

To run DISM tool, follow the steps below:

Step 1: Press “Windows + X” key from keyboard and select “Command Prompt as Administrator”

Step 2: Now, type the following command in command line and hit “Enter” key to execute it

“Dism.exe /Online /Cleanup-Image /Restorehealth”

Step 3: This process will repair System image. Once done, restart your computer and please check if Windows 10 Update KB4561608 Error 0xc000021a is resolved.

Procedure 4: Manually install the Windows updates

Step 1: At first, you need to visit “Windows 10 update history” Webpage where you can notice the logs of all the previous Windows updates that have been released.

Step 2: Note down the ‘KB’ number like KB4561608 or others for the most recently released update

Step 3: Now, you need to visit “Windows Update Catalog website” and search for update specified by KB number you noted down.

Step 4: Download the update depending on System configuration if your machine is 32-bit= x86 or 64-bit=x64

Step 5: Once downloaded, open the download file and install the update

Step 6: After installation, restart your computer to apply the changes. Once done, please check if Windows 10 update error code 0xc000021a is resolved.

You may also read: June 2020 Patch Tuesday Updates For Windows 10 version 2004, 1909, 1903 and 1809


I am sure this article helped you to fix Windows 10 Update KB4561608 Error 0xc000021a” “fix Windows 10 Update Error code 0xc000021a” or “fix Windows 10 security Update KB4561608 fails to install” error with several easy methods. You can choose either one or all procedures mentioned above to fix this error.

If you unable to fix this error with the solutions mentioned above, then it might possible that your System has malware or spyware related issue. In this case, you can scan your System with powerful antivirus software that has the ability to delete all types of malware or spyware, remove faculty software, clean System registry and fix all types of System errors or bugs. You can download the powerful antivirus software via link below.

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