This particular BSOD error can occur due to problematic Windows Updates, corrupted drivers, signature validation failure, or issues with system components. A similar error code STOP 0xC000021A {Fatal System Error} can occur due to Windows Setup.
Fix Blue Screen Error Code 0xC000021A
If the Blue Screen error 0xC000021A occurs, your PC will undergo Automatic repair to resolve the problem. But this has not helped some to address the issue. According to the affected users, the automatic repair did nothing and they saw the Windows Recovery Environment screen after the Automatic repair got finished. On this screen, Windows will show two options, either to restart the computer or launch the Advanced options. On restarting the system, the Boot loop continues and the error occurs again. BSOD errors also occur due to faulty hardware. Hence, we suggest you disconnect all your external devices and restart your computer. You can use the power button to restart your computer after disconnecting all external hardware devices. If this does not help, use the solution provided below:
To perform all the above fixes, you need to boot in Windows Recovery Environment. If your computer does not start in Windows RE automatically, you have to enter Windows RE manually. To do so, press and hold the power button until your PC shuts down. Now, press the power button to turn on your computer. When you see the Windows logo or your computer manufacturer’s logo, immediately press and hold the power button to force shut down your computer. Repeat this process up to three to four times. After that, your computer will automatically boot in Windows Recovery Environment. Now coming back, let’s see the suggested fixes in detail.
1] Copy the hidparse.sys file from system32\drivers folder to system32 folder
The BSOD error code 0xC000021A is associated with Windows 10 version 22H2 KB5021233 Cumulative Update. Microsoft has also acknowledged this problem in an article on its official website. However, you may also see this error code with Blue Screen while installing another patch of Windows Update. According to Microsoft, the cause of the error might be a mismatch between the file versions of hidparse.sys in c:/windows/system32 and c:/windows/system32/drivers (assuming Windows is installed to your C: drive), which might cause signature validation to fail when cleanup occurs. Currently, the Microsoft team is investigating the BSOD error code 0xC000021A and soon Windows 10 version 22H2 users will get an update in an upcoming release. Till then you can use this temporary solution provided by Microsoft.
On the Windows Recovery Environment screen, click on the Advanced Options button.Now, select Troubleshoot.Select Advanced options once again.Select Command Prompt. Your computer may restart to launch Command Prompt.After the restart, you will see the Command Prompt window. If you are asked to enter your device password, enter it.Now, copy the following command and paste it into the Command Prompt. After that, hit Enter.
In the above command, the letter C indicates that the Windows operating system is installed on the C drive. If for some reason, you have installed Windows on another hard drive partition, type the letter of that hard drive partition. After the completion of the above command, type exit and hit Enter. You will see the Windows Recovery Environment screen again. Click Continue to restart your computer. Windows should start as expected. If the error still persists after performing the above steps, go ahead and use the other solutions provided below.
2] Revert all pending actions
As explained earlier in this article, sometimes, Windows does not restart properly due to which the update installation fails. In some cases, this leads to the Blue Screen of Death errors. In such a case, reverting all the pending actions helps. You need to launch the Command Prompt for this purpose. Enter Windows Recovery Environment and launch the Command Prompt from there. We have already explained the steps for the same above. In the Command Prompt window, you will see the following: Now, you have to select the drive on which the Windows operating system is installed. If the Windows OS is installed on your C drive, type C: if it is installed on another drive, say D, type D: and so on. Mostly, the Windows OS is installed on the C drive. Hence, we are considering that the Windows OS is installed on the C drive. Type the following command and hit Enter. Now, type the following command and press Enter. You should see Windows in the directory list shown just after the above command. If Windows is not there in the directory list, the Windows OS is installed on another drive. In this case, you have to replace the letter C with another drive letter. Now, type the following command and hit Enter. Let the above command be completed. After the successful execution, you will see the following message: Type exit and press Enter. This will close the Command Prompt and take you back to the Windows RE screen, where you have to click on the Continue option to restart your PC. See if it helps.
3] Run Chkdsk, SFC, and DISM scans
If the issue still persists, there might be some errors on your hard disk or some of your system image files might have been corrupted. Hence, we suggest you repair your disk and system image files. To do so, you have to launch the Command Prompt by entering Windows Recovery Environment. After opening the Command Prompt, select the drive on which the Windows OS is installed. We have already talked about how to select the drive on which Windows OS is installed in the previous fix. Now, type the following command and hit Enter. After the above command is executed successfully, run SFC and DISM scans. After running all the scans on your system, type exit and press Enter. Now, click Continue to restart your computer. You should see the login screen this time. If not, use the next solution.
4] Disable Driver signature enforcement
This trick has worked for many users. If you still see the BSOD error code 0xC000021A, disabling Driver signature enforcement will surely help you.
5] Go back to the previous build
If a Windows Update causes problems, users have the option to uninstall that update and go back to the previous build. You can take advantage of this feature and uninstall the latest Windows Update. Enter Windows Recovery Environment and select the “Go back to the previous build” option on the Advanced options screen. After uninstalling the Windows Update, the issue should get fixed.
6] Perform a System Restore
System Restore is a useful tool that helps users protect and repair their computer software. It is enabled by default on all Windows computers. When it is enabled Windows creates different restore points automatically. When a problem occurs, you can select any of these restore points to take back your system to the previous working state. Go to the Advanced options screen in Windows Recovery Environment and select the System Restore option. If multiple restore points are created on your system, Windows will show you all those points with the date on which they were created. Select the restore point which was created before you installed the Windows Update.
7] Reset your PC
This is the last option. If none of the above fixes helped you, you have to reset your PC. First, reset your computer without deleting data. If this does not work, you have to completely reset your PC. This action will delete your data I hope this article helps you fix the issue. Read next: How to find which Driver is causing the Blue Screen on Windows?
