This happens when Windows has switched to the privileged mode, and the non-privileged mode subsystems, such as Winlogon or Client-Server Execution Time Subsystem (CSRSS), have failed, and protection cannot be guaranteed.

Because Windows cannot operate without Winlogon or CSRSS, this is one of the few situations where a non-privileged mode service failure can cause the system to stop responding. This can also occur when the computer is restarted after the system administrator has changed the permissions so that the SYSTEM account no longer has adequate permissions to access the system files and folders. The error can also be caused by corruption of the user32.dll file or incorrect system drivers (.sys)

4 Recommendations for the Elimination of BSoD:

1. 0xC000021A STATUS_SYSTEM_PROCESS_TERMINATED may appear due to errors in the code of the operating system itself. Microsoft is constantly working to correct such errors, releasing patches and service packs. Installed the latest update package (Service pack) and the constant updating of the system will save a lot of errors.
2. If 0xC000021A STATUS_SYSTEM_PROCESS_TERMINATED appeared after the newly installed device driver or program. It is necessary to roll back the driver to an earlier version. With programs, things are easier, removing them will eliminate the cause of the failure. The “Run Last Known Good Configuration” option may be useful.
3. If 0xC000021A STATUS_SYSTEM_PROCESS_TERMINATED began to appear after you have connected a new device to the system, then you need to check it for compatibility with your operating system. If the device is compatible, then you need to download the latest drivers from the official website of the manufacturer and install them. If the latest drivers are installed, you need to install an earlier version of the drivers. If the device is incompatible with the operating system, then it is necessary either to change this device or to change the operating system that supports this device.
4. Very often the cause of the appearance of 0xC000021A STATUS_SYSTEM_PROCESS_TERMINATED is a malfunction of the RAM. To test it, you can use testing programs, such as memtest86+.