In this article I will show you how to fix a common blue screen of death with the error code 0xc000021a
This windows stop code 0xc000021a can appear at random times and you will lose any unsaved work when it happens.
When your machine crashes to this stop code you will see the below blue screen. You will then have to restart your machine to recover from this error.
You can view a video of this article by clicking here
Causes and Symptoms of 0xc000021a Stop Code
The stop code 0xc000021a is a bug in the windows 10 operating system where your machine will crash to a blue screen and you will lose any unsaved work and will have to restart your machine.
The error will occur because your computer had an issue writting something to memory and it does not know what to do and this is what triggers the blue screen of death.
The most common causes are misconfigured software or device drivers, or your system has some sort of corruption.
What ever is causing this stop code we can easily fix it.
How To Fix 0xc000021a Stop Code On Windows 10
To fix the 0xc000021a stop code on Windows 10 do the following
- Insert your windows 10 DVD in to your system
- Boot to the DVD. (If your system does not have a DVD drive you can download a windows 10 ISO from the microsoft.com site and make a bootable USB flash drive)
- On the first screen click on “troubleshoot”.
- Next click on “advanced options”
- Then Click on “command prompt”
- A black window should now pop up, in the window type chkdsk C: /f /r this will perform a chkdsk on your system which will /f = Fixes errors on disk, and /r locates and recovers bad sectors. If you get a y/n prompt type y and hit enter. Now reboot your machine and hopefully it will boot correctly now.
Other Methods To Resolve 0xc000021a
If the above did not work for you we have many more fixes that will work which are listed below
Startup Repair
If the previous method didn’t work we need to perform a windows 10 startup repair. Again boot to the windows 10 DVD. On the first screen you get click on troubleshoot.
Next click on “advanced options”
Then Click on “startup repair”
The startup repair program will start and will scan your windows 10 machine and fix any startup issues it finds. When the repair has finished remove the windows 10 DVD from your system and reboot.
Disable driver signature enforcement
Method 1 and 2 should fix 99% of 0xc000021a windows 10 startup issues, but if you are still having issues there are a few more things we can do. Boot to the windows 10 DVD.
On the first screen you get click on “troubleshoot”
Next click on “advanced options”
Next click on “startup settings”
Then click “disable driver signature enforcement” , then hit restart. Monitor the situation and if the BSOD 0xc000021a is not resolved move on to the next step.
Uninstall recently installed software
It is possible that a recently installed software on your machine is causing the stop code 0xc000021a from appearing.
Repeat the steps in method 3 but at the last screen instead of selecting disable driver signature enforcement select enable safe mode and select restart. Hopefully your machine will boot to your windows 10 desktop. If it does click on the start menu then type in programs and select “Programs and Features”
The below window will now popup. Sort the programs by installed on, Now uninstall as many recently installed applications as you can. Now click on the “View installed updates” on the left hand side of the window. This will show you the operating system updates which have been installed. Again uninstall any recently installed updates.
When you are finished uninstalling recently installed applications / updates reboot your system.
Run a SFC Scan
Repeat the steps in method 5 and boot in to safe mode. Now click on the start menu and type in cmd then right click on the program and select “Run as administrator” when the black window pops up type in sfc /scannow and hit enter. This command will scan all protected system files, and replace corrupted files with a cached copy that is located in a compressed folder at %WinDir%\System32\dllcache. When the scan has finished reboot your machine.
Run a DISM Scan
Repeat the steps in method 6 but apart from running the sfc /scannow command from the cmd window type dism/online/cleanup-image/restorehealth and hit enter. This command will check installed windows updates / service packs for issues / corruption. When the scan has finished reboot your machine.
Update Device Drivers
Some times a device driver becomes corupt or has a bug in it which can cause the stop code 0xc000021a. To update your device drivers follow these steps.
- Open up device manager (Click start, type in “Device Manager” and hit enter) Now expand the driver that is causing the issues (Below I am using the network adaptor as the example.)
- Right click on the device and select properties, then click on the driver tab and note down the driver date and version. (We can see below the version is 3.0.2.201)
- Now search on the internet for an updated driver. We are looking for a driver newer than 26/03/2016 or 3.0.2.201. Download that driver and save it to your machine.
- Now head back to device manager and right click on the device and select update driver, Follow the prompts to update.
- Restart your machine after the driver has been updated. Monitor if your machine still has the stop code 0xc000021a issue. If the issue is still happening continue to the next step
Re-Install Device Drivers
Updating the driver should of resolved the issue, but sometimes if the driver is corrupted it needs to be uninstalled and re-installed. To do this follow these steps
- Open up device manager (Click start, type in “Device Manager” and hit enter) Now expand the driver that is causing the issues, right click on the device and select “Uninstall Device”
- When the driver has been uninstalled reboot your machine. This will completely remove the driver from your system.
- The driver should auto install when windows 10 restarts.
- Go back in to device manager and right click on the device and select update driver, Follow the prompts to update.
Run Windows Update
It is possible that the stop code 0xc000021a error has been fixed in a windows 10 update, We will install the latest windows 10 updates to make sure our system has the latest updates.
To update your windows 10 follow these steps
- Click start > Settings
- Next click on Update & Security
- Now click Windows Updates and then click Check for updates
- The latest windows updates will now automatically download and installed
- Reboot your machine
If your machine is still crashing to a blue screen of death and showing the error 0xc000021a then we can try to update windows 10 to the latest feature update.
Run Windows Feature Update
To the latest version (Currently Feature update version 1903) To do this follow these steps
- At the windows 10 desktop
- Click start and click settings (Cog Icon)
- Click on update & Security
- Half way down the screen it should say “Feature update to Windows 10, version 1909” click on Download and install now
- Your machine will now download the feature update, expect this to take around 5 minutes.
- Once the download has completed it will start to install on your system.
- When the install has finished the status should change to Pending Restart, at this time click restart now
Troubleshoot 0xc000021a Stop Code With The Builtin Troubleshooter Tool
Windows 10 has a built in blue screen troubleshooter tool that we can use to troubleshoot the stop code 0xc000021a blue screen crashes. To use the tool follow these steps.
- Click on the start menu and click the Settings app
- Click on Update & Security
- In the left menu click on Troubleshoot
- Under Blue Screen click on Run the troubleshooter
- Now follow the prompts
- The tool will now scan your system and will automatically apply any fixes needed
- Reboot your machine