What is 0xc000021a and How to Fix It

What is 0xc000021a & What Causes It


Screenshot of the 0xc000021a blue screen error

This problem occurs when Windows is updated. So, after the update, it does not start under Windows and displays this ‘blue screen of death’ (BSOD) with an error. There are two files that are the main cause of this error. These files are:

winlogon.exe : As the file name indicates, this file is responsible for the logon and logoff processes within Windows. This file may be damaged by improper adaptation of system files or third-party software. If this file is corrupted, this error will cause the PC to boot to Windows login.

csrss.exe : The second file that causes this error is Csrss.exe. This .exe file belongs to Microsoft Server or Client. This file can also be damaged by this error.

To correct installation error 0xc000021a under Windows 10

1. Create a bootable disk with Windows.
2. Disconnect all peripheral devices.
3. Upgrade via operating system
4. Run SFC
5. Rebuild BCD
6. Deactivate the driver’s signature application
7. Check the hard disk drive status

Solution 1 – Rebuild a bootable disk with Windows.

Let’s start at the beginning. If you can reinstall Windows 10 on another PC, you must try it. This is the best way to check if your bootable drive is bootable. The procedure is the same for the DVD or USB stick, i.e. if you can boot on at least one PC, the problem is on the other PC and the installation drive is probably properly configured and created.

On the contrary, if you cannot boot to a specific device, be sure to create and reboot the bootable disk from scratch with the Windows 10 installation. If you are not sure how to do things correctly, follow these steps:


1. Download the media creation tool here.
2. Connect the USB stick with at least 4 GB.
3. Launch the media creation tool and accept the license terms.
4. Select “Create installation media (USB stick, DVD or ISO file) for another PC”.
5. Select the desired language, architecture and edition.
6. Click Next.
7. select the USB flash drive and click Next.
8. Wait for the installer to download the files and finally you have a properly created and configured bootable drive with the Windows 10 installation.