This error occurs when a user-mode subsystem, such as WinLogon or the Client Server Run-Time Subsystem (CSRSS), has been fatally compromised and security can no longer be guaranteed. In response, the operating system switches to kernel mode. Microsoft Windows cannot run without WinLogon or CSRSS.
The error code 0xc000021a on Windows 8 and 10 is an indication that your PC has come across a problem, hence the need to restart. It usually appears within a BSOD Blue Screen of Death A stop error, better known as a Blue Screen of Death, is an error screen displayed on a Windows computer system after a fatal system error, also known as a system crash: when the operating system reaches a condition where it can no longer operate safely. en.wikipedia.org. And when you encounter a BSOD, this usually means there is a serious issue that has damaged the internal structure of the Windows operating system.
Windows 8/10 had a number of issues from its first release. After a while, Microsoft began to offer updates, some bugs were fixed, but those that weren’t were enough. One of them is associated with each of our hex codes 0xc000021a. This indicates that experts are stating that your computer has experienced a problem and needs to be restarted.
If there are bad clusters on the HDD and on the SSD, this utility will most likely fix Fatal Program Error c000021a. CHKDSK is present in Windows 7 and Windows 8.1. As you can see, CHKDSK can be run from the command line.
If you are unable to boot into Safe Mode, run System Restore and proceed with the recovery of 0xC000021A using Easy Recovery Essentials. EasyRE can fix this error, but you can also run EasyRE like any CD, DVD, or USB stick. To start System Restore in Safe Mode, follow these steps: On the General Advanced Boot Options screen, select Safe Mode with Command Prompt.
Why does windows stop c000021a fatal system error?
The exact Windows error message C000021a stop Fatal System Error might look a little different. But you should finally understand what happened when you see this rare fatal error on your PC screen: The Windows Kernel has detected that the Winlogon.exe or Csrss.exe service processes have failed).
Why do I get system error c000021a in Windows 10?
It is possible that problems may arise when installing plans to a damaged part of the CD hard drive. Of course, you can resort to PC recovery. see if that helps. Also, if you are getting Stop Error 0xc000021a, System Restore immediately stopped working with Windows 10 update, then this is a known issue for Windows 10.
Why is c000021a fatal system error on Windows 7?
If the fatal system error C000021A was due to a boot configuration data infection, this troubleshooting method should resolve it in support of the good. So, these are all the troubleshooting methods you should use to fix Fatal System Error C000021A in Windows 7 and 8.1.
Why do I get a c000021a error on Windows 7?
Windows 7 and Windows 8.1 versions encounter a stop error code C000021A that prevents the boot process. In most cases, users are affected who confirm that the issue occurred after updating their BIOS version. Fatal system error C000021A
What does fatal system error c000021a mean?
Let’s take a specific look at the fatal functional error c000021a blue screen, which is just one of the most common fatal system errors that you can encounter. The Windows logon process ended immediately with status 0x00000403 (0x00000000 0x00000000). The system was closed.
What is c000021a error?
STOP error: c000021a (fatal system error) occurs when the Windows NT kernel fails to register the Winlogon.exe or Csrss.exe assemblies. Usually, when this error takes place, the Windows kernel shuts down the system and generates an uninstall error message. You have incompatible system configuration files on the system.

Ermias is a tech writer with a passion for helping people solve Windows problems. He loves to write and share his knowledge with others in the hope that they can benefit from it. He’s been writing about technology and software since he was in college, and has been an avid Microsoft fan ever since he first used Windows 95.