- Download and install the software.
- It will scan your computer for problems.
- The tool will then fix the issues that were found.

Stop errors for a Windows computer are common. Here is one of these types: Stop Fatal System Error c000021a. The value of the bug is nothing other than the blue screen of death. Sometimes it is also referred to as a kernel failure. BSOD is an abbreviation for this type of error. In fact, the bug is dangerous and you have nothing to worry about. Here is the fix in this article so that you can use your computer normally. Whenever an error occurs on your computer, Windows may have stopped working. Unsaved data is lost and can also damage your hardware. Let me help you fix Fatal Stop c000021a system error in Windows XP / Vista / Windows 7 / 8.1 / 10.
STOP : c000021a { fatal system error}
The Windows Logon Process system process terminated unexpectedly with a status of 0xc06d007e (0×00000000 0×00000000).
The system has been shutdown.
This is the error message that will appear on your computers when the error occurs. Do you know anything about the error? Unless it is a blue screen error. This is an error that will cause your computer to shut down automatically and cause problems. Blue screen errors occur for a reason. In this article, I will help you remove the error from your PC.
Table of Contents:
BCD data recovery.

Actually, this problem can also be caused by corrupted BCD data interfering with the boot process. If this scenario is true, you will be able to solve the problem by using a command line with elevated privileges to restore the boot configuration information and fix the boot sequence.
Many affected users have confirmed that this method works (especially if the problem occurs with every traditional boot attempt).
If you do not know how to do this, follow the instructions below to start the BCD recovery process from the Troubleshooting menu of your version of Windows:
- First, insert a compatible Windows installation media and press any key to boot your computer from it.
- If your computer successfully booted from the Windows installation CD, click Restore Computer.
- On the Recovery menu, click Troubleshooting, and then click Command Prompt in the list of available options.
- In the command line window, type the following commands and press Enter after each command to start the process of restoring boot configuration data:
- Bcdedit / export C: \ BCD_Backup
- ren c: \ boot \ bcd bcd.old
- Bootrec.exe / rebuildbcd
- BootRec.exe / fixmbr
- BootRec.exe / fixboot
- sfc / scannow / offbootdir = c: \ / offwindir = c: \ windows
- chkdsk c: / r
- exit
Updated: April 2025
This tool is highly recommended to help you fix your error. Plus, this tool offers protection against file loss, malware, and hardware failures, and optimizes your device for maximum performance. If you already have a problem with your computer, this software can help you fix it and prevent other problems from recurring:
- Step 1 : Install the PC Repair and Optimizer Tool. (Windows 10, 8, 7, XP, Vista).
- Step 2 : Click Start Scan to determine what problems you are experiencing with your computer.
- Step 3 : Click Repair Allto resolve all problems.
Wait for the process to complete, then reboot your computer. Make sure that your computer can boot normally after the next boot process completes.
Locate the corrupted files

- Open a command prompt by typing cmd in the search box. Type here.
- Then click Open at the command prompt.
- Enter the following command sfc / scannow and press Enter.
- Note, however, that this process may take several hours if you are using a PC/laptop with a hard drive.
- However, when you have an SSD installed on your PC, the file search may be a little faster than usual.
- Once the process is complete, be sure to restart your computer immediately.
System Restoration

This means that you can restore your system to a previous state when no critical system error occurred on the PC. All functions work as before.
The user has to manually create a new restore point. Then you need to restore the system to this restore point. This also means that you can change the system restore configuration. Old restore points are deleted. You can restore the system weeks before the fatal system error occurred. Note that files stored on volumes are not tracked, copied, or restored.
Usually drivers, registry and system files with extensions such as .exe, .dll can be restored to a previous state where the system actually worked correctly.
APPROVED: To fix Windows errors, click here.