This guide explains how to fix the STOP CODE 0xc000021A error code. If you’re having trouble booting into Windows 10, it could be caused by a number of issues. In this article, we’ll show you how to find out what’s wrong with your computer and fix the problem.
Table of Contents:
How to fix 0xc000021a BSOD error on Windows 10
0xc000021a is one of the most common Blue Screen Of Death errors on Windows 10 PCs. This issue occurs due to corruption of some important system file. When the operating system detects an error, it switches into kernel mode. In such cases, it becomes very difficult to troubleshoot the problem because there is no specific reason behind it. However, we can easily identify the cause of the problem. We can even solve the problem without having to install third-party tools. All you need to do is follow the steps mentioned below.
Steps to Fix 0xc000021a Error on Windows 10 PC
1. Restart Your Computer. Troubleshoot > Advanced Options > Startup Settings > Restart.
2. Press and hold Shift key while restarting your computer.
3. Select Safe Mode option from the list of options displayed on screen.
4. Click Next button to continue.
5. Once you reach the desktop, open Command Prompt window by pressing Win + X keys together.
1. Start Windows 10 in Safe Mode with Networking
0xc000021a error occurs due to some problems in the mismatched system files. If you cannot access your PC normally, try starting it in safe mode with networking features. You can do this by pressing F8 key repeatedly while booting up your computer.
2. Click “Start”, type “cmd” in the Search box, and press Enter.
3. In command prompt window, type “cd %systemroot%\System32”. Press Enter.
4. Type “regedit” without quotes and press Enter.
5. Find regedit.exe file in the list and double-click it.
6. 7. Delete the following values:
2. Clean boot Windows 10
When you start up your Windows 10 PC, it loads everything needed to run smoothly. This includes the operating system itself, applications like Internet Explorer, Microsoft Edge, and even the desktop background image. If something goes wrong during the loading process, however, things could go awry. For example, if there are too many files open, the program might crash. Or, if you don’t shut down properly, the hard disk might become damaged. In either case, you’ll want to clean out the clutter before you proceed. Here’s how to do it.
Step 1: Shut Down Your Computer
Before you begin, make sure your computer is turned off. You won’t be able to access your data if you’re still logged in.
Step 2: Open Task Manager
The easiest way to open Task Manager is to press Ctrl+Shift+Esc. Step 3: Click Processes Tab
Once you’ve opened Task Manager, scroll down to find the list of running processes. Look for anything named explorer.exe. If you see it listed, close the window.
3. Run Startup Repair
If you’re having trouble getting Windows 10 to start up properly, it might be time to use the built-in startup repair tool. This tool runs automatically whenever you turn on your computer, and it helps fix common issues like missing drivers, corrupt files, and registry errors. If you don’t want to wait for the tool to finish repairing your system, you can use an installation disc or USB drive to run it manually.
Here, you’ll find options to boot into Safe Mode, Troubleshoot, and Reset Your PC. You can also download the free version of Microsoft’s System Restore utility to help you recover your machine back to its previous state. To do this, head over to www.microsoft.com/systemrestore and follow the instructions there.
How to create Windows 10 installation media (on a working PC):
If you are looking for how to make a bootable Windows 10 installation USB flash drive, we have some tips for you. You can use the free Microsoft Windows 10 ISO image file to do just that. If you don’t already have one, you’ll need to download the ISO file from here. Once downloaded, simply copy all the contents of the ISO file onto a USB flash drive. We recommend using either a 16GB or 32GB USB stick. Formatting the USB drive is optional; however, we highly recommend doing so. This way, you won’t run into issues later on when trying to install Windows 10.
Once formatted, insert the USB flash drive into the target machine and restart the system. When prompted, select “Try Windows without installing”. After the setup process completes, you will be able to access Windows 10 via Live Mode. From there, you can perform a clean install of Windows 10.
How to run Startup Repair (on the malfunctioning PC):
If you are having trouble booting up Windows 10, try running Startup Repair. This tool will scan your hard disk for problems and fix them automatically. You don’t even need to restart your computer.
To do it, follow these steps:
1. Plug the external USB storage device into your PC.
2. Open Start Menu. Type “recovery.” Select “Recovery options,” and select “Startup Repair.”
3. Click “Repair my Computer” button.
4. Wait while the system scans your entire hard disk for errors. After scanning finishes, click “Fix All Problems” button.
5. Restart your PC.
4. Disable Driver Signature Enforcement
Unsupported drivers can lead to serious problems on your computer like blue screen errors like 0xC000021A.
This issue happens when you install Windows 10 version 1803 or later. If you are running Windows 10 version 1903 or later, you must disable driver signature enforcement before you install any new drivers. To do this, follow these steps:
1. Open Device Manager.
2. 3. Right-click each device, and select Properties.
4. Select the Driver tab.
5. Uncheck Enable Driver Signature Enforcement.
6. Close Device Manager.
But you can fix this by disabling Driver Signature Enforcement:
The Microsoft Windows 10 operating system includes a feature called Driver Signature Enforcement (DSE). This feature helps protect against malware infections by preventing drivers from being loaded unless they are digitally signed by Microsoft. If DSE is enabled, it requires signatures to be installed on each device that uses a particular driver. For example, if a computer has a graphics card and a sound card, both of those devices must have valid digital certificates installed before the operating system loads the correct driver for either one.
If a malicious program tries to load a driver without a certificate, the operating system displays a warning message letting the user know that there is something wrong with the driver. In addition, the operating system prevents the driver from loading completely.
However, some people have reported seeing blue screens of death (BSOD) while trying to use certain programs. These BSODs occur because the operating system cannot properly identify the driver causing the issue. As a result, the operating system crashes.
In many cases, the cause of the problem is due to a corrupt registry file. A corrupted registry file causes problems like this because it contains incorrect information about the hardware configuration of the machine. When the operating system attempts to load a driver, it checks the registry file to see what type of hardware is present. If the registry file is missing or damaged, the operating system does not recognize the hardware correctly and fails to load the appropriate driver.
To resolve the problem, follow these steps:
1. Open Registry Editor by pressing Windows Key + R, typing regedit into the Run dialog box, and clicking OK.
2. Navigate to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\LanmanServer\Parameters.
If it doesn’t work, you can use Command Prompt:
In Windows 10, there are three ways to access the command prompt. You’ll see something like this:
To disable Secure Boot in Windows 10, you must do one of the following things:
1. 2. Open up the Command Prompt window by typing cmd into the Search box and hitting Enter
3. Press Ctrl+Alt+Delete and select Task Manager
4.
How to disable Secure Boot from the UEFI firmware settings:
If you want to use Windows 10 Home edition, it requires Secure Boot enabled. If you are running Windows 10 Pro, Enterprise, or Education editions, you must disable Secure Boot to install Windows 10. You can do this by opening up the BIOS setup utility (F2 key during startup), selecting “Security,” and disabling Secure Boot. Once disabled, restart your computer and select the Windows installation media to start the process.
When you turn off Secure Boot there is a risk of installing an unknown operating system. This could cause problems such as boot loops, corrupted files, and data loss. To avoid this issue, make sure you have backed up important files and installed a recovery disk.
5. Fix hard drive corruption
Hard drive failure is one of the most common reasons why you are getting error code 0xC000007B. This error usually occurs due to physical damage to the storage device. You can fix it by running CHKDSK command. If you do not know how to run CHKDSK command, follow our guide: “How to use Windows 7 Command Prompt”.
6. Repair corrupt system files
There are many reasons why you might want to fix corrupt system files. For example, you might be having trouble booting into Windows 10 because it cannot find the operating system file. Or maybe you’re trying to install a program that requires some missing files. In either case, repairing corrupt system files is one of the best ways to resolve the problem. This article explains how to do just that.
7. Update old drivers
Drivers are important for every PC because they help improve performance, increase safety, and provide essential functions such as WiFi connectivity. However, old drivers can cause issues during Windows startup. This problem occurs when you try to start up the operating system without having updated the device drivers. To resolve this issue, you must install the latest version of the drivers. If you don’t want to do it manually, you can always download an automatic driver updater tool.
There are many different ways to update drivers. One of the best ways is to use an automatic software updater. These tools scan your computer for outdated drivers and automatically download and install the newest versions. Some of the most popular ones include DriverMax, Driver Easy, and Driver Alert.
8. Roll back incompatible drivers
Incompatible drivers are those that don’t work well with Windows 10. They’re often caused by third-party applications that install outdated drivers. If you’ve recently installed a new piece of hardware, such as a printer or hard disk drive, it’s possible that you’ll find yourself unable to use some features because of missing or incompatible drivers.
To fix this problem, roll back to an earlier version of Windows 10. You can do this by pressing the Start button, typing “Windows Update,” clicking Settings, and selecting Change settings. Then select Recovery under System. Scroll down to find the option to go back to previous versions of Windows. Select the one you want to use, restart your computer, and follow the prompts to complete the process.
Click More info.
9. Repair the system registry
The command prompt window opens up. You are prompted to select a restore option. Select the “Repair” button.
– Press Ctrl+Shift+Esc keys together to open Task Manager.
– Click the Processes tab.
– Find the process named Microsoft.WindowsUpdate_v4.1.0.0_x86fre_en-us_14393. This is the core component responsible for updating the operating system. Right-click it and choose End task.
– Restart the computer.
– Open Command Prompt again.
– Run the following command: regedit.exe /u “%SYSTEMROOT%\system32\Config\SAM”.
– Delete the file called SAM.
– Close Registry Editor.
– Reboot the computer.
10. Fix BCD
Boot Configuration Data (BCD) stores information about how to boot into Windows 10. This includes the location of drivers, system files, and settings. When you install Windows 10, it creates a backup copy of the BCD called the “Windows Recovery Environment.” In case something goes wrong during installation, you can restore the BCD to recover your PC.
If you receive the 0xC000021A error message while trying to start up Windows 10, you might try repairing the BCD. To do this, open Command Prompt and type bcdedit /fixboot.
You can also fix the BCD with a third party tool like WinRE/Recovery Console.
11. Uninstall third-party apps
Uninstalling third-party apps can sometimes lead to unexpected issues, especially if you’re not familiar with how it works. If you’ve been having trouble getting rid of unwanted apps, try following our guide to uninstall them safely.
#1: How to Remove Apps Manually
If you want to completely delete an app without reinstalling Windows, follow these steps:
Step 2: Type “appwiz.cpl” into the command prompt window and press Enter key
Step 3: Press Enter again to open the AppWizard dialog box
12. Uninstall system updates
System updates are designed to fix bugs and improve performance. Some updates are optional, while others must be installed to make Windows work properly. However, some updates can cause problems if they aren’t removed correctly. If you want to keep certain updates, it’s important to uninstall old ones before installing newer versions.
Windows 10 includes a built-in tool called Update Assistant that helps you find out about pending updates and install them automatically. You can use this tool to see whether there are updates ready to be installed, and to check for updates manually. This will show you all the updates that are ready to be installed.
If you don’t want to wait for automatic updates, you can download and run the Microsoft Update Catalog app. Then select Download updates manually from the left pane. Select the updates you want to install and follow the prompts.
Click Remove next to each update you no longer want.
You can also use the command prompt to uninstall updates. For example, type winupdate /uninstall 90400.
13. Unplug external devices
The next step is to make sure that nothing plugged into your computer is interfering with it. You’ll want to unplug all the devices attached to your PC, including hard drives, USB ports, power supplies, speakers, printers, network cards, and anything else that could cause interference.
If you still experience issues after unplugging everything from your laptop, open up Device Manager and look for anything that looks suspicious. If there is something listed under “Other Devices,” double-click on it to launch the Properties window. Click on the Hardware tab, and scroll down to the bottom to find a section called “Device Status.” Check whether the status reads “Not Working” or “Offline.” If it says “Online,” then you know that the device is working fine; however, if it says “Offline,” then you probably have some sort of hardware issue.
To fix the problem, you’ll need to update your BIOS. To do that, follow these steps:
1. Open up the Control Panel.
2. Select System and Security.
3. From here, select Power Options.
4. Under Choose What Closing Your Computer Does, choose Shut Down.
14. Reset BIOS
Resetting the BIOS will ensure that you are running your computer correctly. If the problem persists after doing so, you may want to try one of the following methods.
This method is recommended if you cannot find the cause of the problem. You can use it to test whether there is something wrong with your hardware.
Do not attempt to fix issues without knowing what caused them. For example, if you see a warning about a hard disk failure, do not proceed unless you know how to repair such a problem.
To prevent further damage, shut down the computer immediately after performing the steps described above.
1. Power off the PC
2. Remove the battery from the motherboard
3. Insert the battery into the motherboard
15. Update BIOS
The best way to make sure you’re getting the most out of your hardware is to keep it running smoothly. To do that, you’ll need to update the BIOS on your motherboard. This process involves copying over the current firmware to a backup location, updating it, and then restoring the backup to replace the old one. Here’s how to do it.
16. Disable Fast Boot
Fast Boot is a feature in Windows 10 that allows you to quickly start up your PC. This feature is designed to speed up the startup process, especially for those who are experiencing slow boot times. However, there are some drawbacks to disabling Fast Boot. If you do decide to disable Fast Boot, make sure to perform a clean install of Windows 10 before doing anything else. You’ll want to ensure that everything is backed up properly before proceeding.
17. Enable Legacy BIOS boot
In Windows 10 version 1803, Microsoft introduced a feature called “Secure Boot.” This feature prevents older operating systems like Linux from running on newer computers. Some computer manufacturers use Secure Boot to prevent you from installing another OS on your PC. If you want to install Linux on your system, you’ll need to disable Secure Boot.
To do this, follow these steps:
1. 2. 3. Select UEFI Firmware Settings
4. Disable Secure Boot
5. Restart your computer
6. Install Ubuntu Linux
7. Reboot
8. You’re done!
18. Inspect Event Viewer
Event Viewer is a powerful troubleshooting tool that provides detailed information about Windows errors. This article explains how to use it to find out what went wrong during installation, application startup, or shut down.
19. Roll back Windows 10
Rolling back to a previous version of Windows 10 is easy. Just follow the steps below.
1. Open Settings
2. Click Update & Security
3. Scroll down and select Change PC settings
4. Select Recovery
5. Choose Go Back
6. Follow the instructions to go back to an older version of Windows 10
7. Save changes and restart your computer
NOTE: If you are having trouble finding the recovery options, it might be because you don’t have enough free space on your hard disk. To fix this issue, please refer to our guide here.
20. Run a malware scan
Malware infections are one of the most common problems faced by computer owners today. They can make it difficult to use your system without causing harm. If you suspect your machine might be infected, we recommend running a full anti-malware scan immediately.
To do this, download Malwarebytes Anti-Malware Free Edition (MBAM). This program will detect and remove many types of malicious software including viruses, spyware, adware, Trojans, rootkits, dialers, keystroke loggers and worms. You can download MBAM here.
Once installed, run the program and follow the prompts. When finished, select “Perform Quick Scan”. After scanning completes, press “Quarantine Selected Items”, and then let MBAM finish cleaning up your system.
If you’re having trouble getting MBAM to start, try restarting your computer.
21. Check the system memory
Windows Memory Diagnostic is one of the most important tools you can use to make sure your computer is running smoothly. Every version of Windows includes this tool, but it doesn’t always show up automatically. If it does, just follow these steps to see how much RAM your PC has installed.
Step 2: In the System Information window, select Performance tab
Step 3: Select “System Physical Memory” under Hardware section
Step 4: Scroll down to “Available physical memory:” and note the amount listed
Note: Your total physical memory might differ based on what programs are open and running. For example, if you’re watching videos online, the amount of free space used by those files will reduce the amount of RAM available to run your operating system.
How to use Windows Memory Diagnostic:
If you are prompted for an Administrator password or confirmation, type the password or provide confirmation. In the Command Prompt window, type runmemdiag.exe /extended and press Enter.
The System Information dialog box appears. Select the Performance tab. You can select additional tabs to display information about hard disk drives, optical drives, network adapters, etc., but we will focus on the Memory section.
In the Memory section, you can see how much physical memory is installed on your computer. Your total memory includes both RAM and video memory. For example, my laptop has 4 GB of RAM and 2 GB of video memory. This totals 6 GB of memory.
You can also see how much free memory is available. Free memory is used by applications and programs that do not require memory. For example, I have 3 GB of free memory because I am running Microsoft Office 2016.
If you want to know how much usable memory is available, subtract the amount of free memory from the total amount of memory. For example, if there are 5 GB of total memory and 3 GB of free memory, the remaining 2 GB of memory is usable.
To change the size of the free memory, follow these steps:
1. Open the Control Panel.
22. Run System Image Recovery
To access the Troubleshooter menu, press the F2 key repeatedly until the boot option screen appears. Follow the onscreen instructions to complete the process.
23. Use a Linux live distro
If you want to try out Linux without installing it on your computer, there are several options. You can use a Live CD/DVD, which boots up into a version of Linux that runs off a disc rather than being installed onto your hard disk. Or, you can download a version of Linux and run it directly from a flash memory device such as a USB stick. In this article we’ll show you how to do both.
Live CDs
A Live CD is basically an operating system that loads itself into RAM while running off a CD or DVD. This makes it possible to test out Linux without permanently damaging your existing OS.
You can find many different versions of Linux preinstalled on Live CDs, including Ubuntu, Fedora, Mint, etc. They’re usually very easy to set up and use because they don’t require much configuration. However, they won’t work properly unless you connect them to the internet. If you want to try out a Linux distribution without having to plug in a monitor, keyboard, mouse, and printer, you can always opt for a Live CD.
To make one yourself, you’ll need to burn a copy of the Linux ISO file to a blank CD or DVD. There are plenty of tools online that can help you do this. For example, here’s what you’d see if you used the program Brasero to burn the Ubuntu 16.04 LTS ISO file to a CD.
The easiest way to create a Live CD is to just insert the media into your computer and reboot. When your computer restarts, you’ll see the option to choose whether to start Windows or load the Linux Live CD. Choose the latter, and you’ll be presented with the following screen.
Here you can select your language, enter your username and password, and choose either to automatically log you into GNOME or KDE. Once you’ve done that, you’ll be able to access the desktop environment.
How to create an Ubuntu live disk with Rufus:
Create a bootable Ubuntu LiveDisk with Rufus
Connect a USB flash drive to you computer and make sure to backup all important log files before formatting it.
Select the USB drive letter
Now we are ready to format the USB drive. Open up Rufus again and select the “Format” option. Click on the drop down menu next to Format Type and choose FAT32.
Click Next and name the USB Drive as you wish. Then click on Start.
Once the process is done, disconnect the USB drive and insert it into another PC where you want to install Ubuntu. Now open up Rufus again, go to the Options tab and change the Target Device Path to /dev/sdX#. Replace X with the number of your USB drive. If you don’t know what the number is, just plug the USB drive into your PC and check out the properties of the device.
Then click on Start. This will start creating the installation media. Once it finishes, you’ll see a screen like below. You can now close Rufus.
How to boot Ubuntu from the USB flash drive:
Boot into Ubuntu from the USB Flash drive
Unplug the flash drive from the working computer and plug it into the broken one.
Before Windows starts, press F2 to enter the BIOS settings.
Select “USB Device”, set the priority to “High” and enable “UEFI”.
Save and exit.
Windows should now start up again. If you see the error message “No operating system found”, please follow the instructions here.
24. Reset Windows 10
Reset Windows is easy to do. If you know where to look, it’s possible to access the BIOS settings without having to call tech support. This guide explains what to look for and how to reset Windows 10.
After resetting, you’ll need to configure your computer again. You’ll want to make sure everything is set up correctly.
Windows stop code 0xc000021a can be fixed
0xc00002a is one of those blue screens that pop up every now and again. If you ever see it while trying to start Windows 10, don’t panic. The good news is that there are plenty of solutions to help you out. Here’s how to fix the problem:
1. Restart Your Computer
If you’ve been experiencing problems with your PC recently, restarting could be just what the doctor ordered. This step is especially useful if you’re having issues starting your system. After you reboot, check to make sure that your hard disk isn’t failing. Try running Disk Checker, which will scan your hard drive for errors.
2. Use Safe Mode
You might notice that your PC boots straight into safe mode. If that happens, you can access safe mode by pressing F8 during startup. When you do, you’ll be presented with a menu where you can choose Safe Mode. Once you select it, you won’t be able to use your mouse or keyboard. However, you’ll still be able to view files and folders on your desktop.
3. Reinstall Windows
This is probably the most drastic solution, but it’s definitely worth considering. If you’re willing to lose everything on your machine, reinstalling Windows will allow you to start over without losing anything important. All you need to do is download the latest version of Windows 10 from Microsoft’s site.