21 July 2016

How to fix error code: 0xC000021A in Windows 8, 8.1, 10

fix error code: 0xC000021A

How to fix error code: 0xC000021A in Windows 8, 8.1, 10


For a better understanding of the boot issue, let me know if you make any recent hardware or software changes on the computer prior to this issue?


The STOP 0xC000021A error occurs when either Winlogon.exe or Csrss.exe fails. This issue could have occurred due to these reasons.



  1. Due to damaged system files.
  2. Due to bad sectors on hard drive.
  3. An incompatible third-party program has been installed.


Try the steps listed here and check if it helps.


Method 1:
I would suggest you to disconnect all the external devices other than mouse and keyboard and check if it helps.

Method 2:

If you have not tried to boot the computer from an installation or repair disk. I would suggest you to boot the computer from an installation or repair disk, and then try to perform Startup Repair or Check Disk from WinRE.


If your computer is not configured to start from a bootable USB, CD or DVD, check the information that came with your computer. You might need to change your computer's BIOS settings. For information about which settings to change, check your computer manufacturer's website. For more information about BIOS, see BIOS: frequently asked questions.



Note: Modifying BIOS/complementary metal oxide semiconductor (CMOS) settings incorrectly can cause serious problems that may prevent your computer from booting properly. Microsoft cannot guarantee that any problems resulting from the configuring of BIOS/CMOS settings can be solved. Modifications of the settings are at your own risk.


Step 1: To perform Automatic Repair, follow these steps.

a) Insert the media such as (USB or DVD) and restart the computer.

b) Press F12 key (typically this is F12, but it can differ between computer manufacturers) and choose the drive that you inserted the installation media into.

c) Once the Windows Setup window appears, follow these steps:
d) Click Next and select Repair your computer.
e) You will then see a blue screen and an option to choose. 
e) Choose the option Troubleshoot and select Advanced options.
f) You may choose Automatic Repair from Advanced boot option.



Step 2: Run check disk from WinRE and check if it helps.

a) Insert the media such as (USB or DVD) and restart the computer.

b) Press F12 key (typically this is F12, but it can differ between computer manufacturers) and choose the drive that you inserted the installation media into.

c) Once the Windows Setup window appears, follow these steps:
d) Click Next and select Repair your computer.
e) You will then see a blue screen and an option to choose. 
e) Choose the option Troubleshoot and select Advanced options.
f) Select Command Prompt.
g) In the command prompt, type ‘chkdsk /r’ and press Enter.




Note: While performing chkdsk on the hard drive if any bad sectors are found, it tries to repair that sector and if any data available on that might be lost.




Hope this information helps. 

Reply to the post with updated status of the issue to assist you further.