Windows 10 Blue Screen of Death Error Code 0xc000021a

Blue Screen of Death (abbreviated: BSOD) or error code 0xc000021a, also known as a stop error, occurs whenever Windows detects a series of errors and cannot recover from them. Therefore, Windows will shut down or restart itself to avoid further damage.

Any version of Windows can encounter blue screen errors, definitely including Windows 10.

Windows 10 BSOD errors can occur on boot or after an upgrade, including software upgrade, drive upgrade, and system upgrade. It can also occur after logging in or when upgrading to Windows from Windows 7 or 8.1.

Error Code 0xc000021a: An Overview

Tip: Blue Screen of Death is also known as BSOD. However, the causes for the two errors are different. For more information about the Windows 10 blue screen, please read this post “Here are the solutions for how to fix Windows BKSOD error“.

Windows 10 blue screen often comes up with an on-screen error. Such as:

However, sometimes it’s just a blue screen or the one with a few rotating dots:

Sometimes it just happens once and you won’t see it when you restart, but sometimes you get into the blue screen on startup.

So why is Windows 10 BSOD error occurring? How can we fix the problem quickly? You need to know that, right? Read this post and then you can find out what you want.

Similar Post: https://errorslab.com/0xc000021a-2/

Windows 10 Error Code 0xc000021a: what’s causing it?

Hard drive-related causes:

  • External hard drive is installed improperly
  • One or some of the hard drives are defective, such as RAW, CPU and internal hard drives
  • New hard drives are not compatible with your BIOS.
  • There is not enough free space on the partition where Windows will be installed
  • Your hard drive drivers are out of date, particularly graphics drivers.
  • An upgrade of Windows or a program that is incompatible is being installed.
  • Virus attack
  • Startup files are damaged or destroyed
  • System file will be damaged
  • Windows bug
  • BIOS is out of date
  • BIOS is incorrectly configured or overclocked.
  • Software-related causes:

Now that we understand the causes of Windows 10 stop errors, let’s talk about how to fix the problem next.

Windows 10 Error Code 0xc000021a: How to Fix It Quickly


Before you start repairing Windows 10 blue screen of death, it is better to first backup any useful data that is stored in the partition where Windows will be installed, which will help you avoid data loss. It’s also considered the first step when you need to reinstall Windows.

So how can you Backup Data on Windows?

When Windows finally starts, just transfer the files from that partition. If Windows 10 error code 0xc000021a reboot loop is preventing you from accessing the desktop, follow the guide below.

Back up data from non-bootable Windows before fixing Windows error code 0xc000021a
To make such a backup, you need to create bootable media of MiniTool Partition Wizard, which is available in paid editions of MiniTool Partition Wizard.

First, purchase a license for MiniTool Partition Wizard so that you can use the Bootable Media Builder function on the toolbar.

Second, boot your non-bootable computer from MiniTool Partition Wizard’s bootable media to its main interface.

Third, make sure there is unallocated space to back up the backup copy of C drive before using the Copy Partition feature. Then select drive C and choose “Copy Partition” to continue. Because the instructions are so comprehensive on each interface, we won’t give you any details here.

Tip: 1. Here you need to observe the capacity, used space, file system and other partition properties more closely to find out C drive. Because the drive letters here in WinPE are different than in normal surroundings.

Tip: 2. If no space is marked as unallocated, select a large partition and use the move / resize function to shrink that partition and create unallocated space.

Then we will discuss about the solutions to Windows 10 error code 0xc000021a.

Windows 10 Error Code 0xc000021a on startup: how to quickly fix it

Windows 10 stop errors mostly occur while booting, some of which could be fixed after a reboot. However, in most situations you will be stuck in the reboot loop and have to shut down the computer manually.

To fix such Windows BSOD errors, please think about the operations you were doing right before the BSOD and then reverse the operation.

Solution 1: If you get BSOD after installing an update, program or driver on Windows

If Windows 10 error code 0xc000021a occurs after installing Windows update, driver or application, please uninstall it and check if Windows can start normally or not.

  1. Windows boots successfully after restarting.

To uninstall Windows Update, please click the “Start” button, select “Settings”, find “Update & Backup”, then click the following buttons one by one: Windows Update> Advanced Options> View Update History> Updates uninstall. You will then get the following interface:

Here please right click on the update that can lead to the BSOD error and uninstall it. Of course, you can also double-click the update and uninstall it.

To uninstall hard drive drivers, right-click the Start button and select Device Manager. You will then get the following window.

Here, please find the device that needs to be uninstalled and right click on it, select “Uninstall”, click “OK” to determine the uninstallation. Then Windows will uninstall the device and delete its drivers.

To uninstall a program, simply open Control Panel and choose Program> Uninstall Programs.

Then right click on the program and select “Uninstall”. Then click “Yes” to confirm the uninstallation.

After uninstalling incorrect Windows updates, device drivers or programs, users should be able to boot Windows properly.

However, if you forget the names of any updates, drivers, or software, simply try uninstalling the ones that were ultimately installed by checking their installation date.

  1. You get stuck on Windows BSOD restart loop.

Since Windows is not bootable under this circumstance, you should uninstall Windows updates, drivers or programs in safe mode.

Safe mode is a diagnostic mode for Windows that starts your computer in a restricted state. Only the basic files and drivers necessary to run Windows will start up. This will help us to see if the problem is due to a conflict with third-party programs, Microsoft

It should be noted, however, that pressing F8 or F8 + Shift may not start the computer in Safe Mode. This is mainly because Windows 10 comes with a very fast startup process. However, it doesn’t matter if you press “F8” or “Shift + F8” first and then use the Windows 10 installation CD or the recovery drive.

Start your computer from the Windows 10 installation CD or the recovery drive and click Next> Computer Repair Options> Troubleshoot> Advanced Options> Startup Settings> Restart to open the window below when using the installation CD:

3. If You get this BSOD error even after you did nothing

First, please check your hardware devices to see if they are properly connected. If they are not fully slid into their slots, BSOD is very likely to occur.

If this is not the cause, please check whether there is not enough space on the C drive. If Windows is bootable after restarting, download MiniTool Partition Wizard Free. If Windows does not start, you need to use the MiniTool Partition Wizard boot media. This program clearly shows the free space in each partition.

If your C drive is running out of space, use the Partition Wizard’s Extend Partition feature to extend it. We suggest that at least 15% capacity of drive C must be kept free at all times.

Then you can try virus cleanup when drive C has enough space. Some viruses attack your MBR (Master Boot Record) or boot sectors, which can lead to Windows 10 error code 0xc000021a.

It’s easy to scan our computer for viruses when Windows is bootable: just launch the antivirus software, scan for viruses and remove them. If Windows is not bootable, you need to do it in Safe Mode. We recommend enabling Safe Mode with Networking.

If viruses aren’t the cause, try:

  • Set the BIOS to its original state
  • Upgrade BIOS to the latest version
  • Upgrade Windows to the latest version
  • Repair boot by entering the commands “bootrec / fixmbr”, “bootrec / fixboot” and “bootrec / rebuildbcd” in the command prompt of the Windows installation CD or the recovery drive.
  • Perhaps one of these solutions can solve your problem.