Windows Defender Error Code 0x800B0100

error code 0x800B0100

During the time you try to start Windows Defender, you are facing the error code 0x800B0100 on your PC. As a result of this error, you cannot enable the Defender app on your Windows PC. There can be so many reasons for this error. If your computer system is infected by some kind of virus, the error can occur

It also occurs when a third-party antivirus program is installed on the system. Since there are multiple reasons for the error, there must be enough solutions. Therefore, in this article, we are going to discuss the methods to fix Windows Defender error code 0x800B0100 easily.

Methods to fix Windows Defender error code 0x800B0100

Regardless of the version of the Windows operating system, this specific error can occur at any time. As discussed earlier, there is no solid reason for this problem. 

However, in this section, we are going to try some methods to fix the problem as soon as possible. You can follow all or all of them to get the fixed Windows Defender error code 0x800B0100 that you have encountered when using the Defender on your PC.

Method 1 – Perform a clean boot

This is one of the most useful troubleshooting steps to resolve the 0x800B0100 error in your Windows Defender. Starting Windows with minimal features can help you fix the problem and you can do it with a clean start. If a third party application is causing the problem, you will easily learn to know.

It will help you to disable all third-party applications to ensure that it starts safely. Now you need to check if the Defender opens and works or not. If it works fine, it means that you are facing the error due to a third-party application you may have installed. So, if you don’t know how to start Windows with the minimum function, follow the steps mentioned in the section below.

Steps to follow to perform a clean boot

  • First, press and hold the Start button with the R key on the keyboard.
  • While the Run window opens, type ‘MSConfig‘ in the input field and then press the Enter key to go to the next step.
  • Go to the Services tab in the System Configuration window to make changes to it.
  • In this section, you will find “Hide all Microsoft services” with a checkbox in front of it. You must mark it checked.
  • Since all Microsoft services are hidden, click the Disable All button in the bottom right corner.
  • After that, go to the Startup tab and click on Task Manager to open it.
  • Right-click on the application associated with an external source and disable it. If there is more than one application, disable them all.
  • Close Task Manager, and then select OK to save the changes you have made.

Once you are done with all of the above steps, restart your computer. It allows you to use your PC with the minimal features enabled in it. Now try to open Windows Defender and check if the problem still occurs.

If you no longer face the error, it means that third-party applications are interfering with your system. After you know the reason, you need to change all the settings as they were. To do that, you can go through the next section.

Steps to follow to undo the changes

  • Open the System Configuration window by following the steps in the section above.
  • Once it opens, select the General tab to view the different options.
  • From the Normal Startup menu, select and click the Services tab of that window.
  • Now uncheck the option you checked earlier when performing a clean boot. It usually says ‘Hide all Microsoft services’ and it appears with a checkbox on it.
  • After that, click Enable All in the bottom right corner of the tab.
  • Click the Startup tab and then open Task Manager to enable all the applications you have disabled.
  • If you are prompted in this process to restart your PC, do so.

These are the steps to reset the Windows settings to boot it in normal mode. Following such steps should help you solve the problem.

Method 2 – Check the Windows Defender service

If the above method failed to fix the error for you, try this one. Sometimes it happens that the Windows Defender services are down. In such circumstances, you may encounter the error 0x800B0100 on your computer.

Therefore, you need to make sure that the Windows Defender services are running or enabled. Usually this happens because of the virus infection on your system. To ensure that the services of the Windows Defender application are running, go through the steps mentioned in the next section.

Step 1:

At the beginning of the steps, press the Windows Home button with the R key to open the Run window. While opening, type ‘services.msc’ in the search box and then press Enter to continue with the steps.

Step 2:

Once the Services window opens, try to locate Windows Defender in the displayed list on it. If you can locate it, open it with a double left click.

Step 3:

A new window will open of the Windows Defender services where you need to check a few settings. Make sure that the startup type has selected the Automatic option and that you can find it in the top left corner of the window. You must also ensure that the Service is in Started state.

Step 4:

Then check for the ‘Windows Defender Advanced Threat Protection Service’ whether it is active or not, as it guarantees the advanced protection of your PC. Now look for another service called ‘Windows Defender Network Inspection Service’ if it is enabled and set to automatic. Sometimes the options are grayed out, but don’t worry, it depends on the configuration of your system.

By following the steps mentioned in the section above, you should no longer get the error message. If you have successfully completed the steps, the Windows Defender application should work fine. And it should give you the desired result which is the fixed Windows Defender error code 0x800B0100 on your Windows PC.

Method 3 – Run SFC scan

When there is an error in Windows PCs, you have to use the SFC tool because it is so useful. It can check if there corrupted system files on your PC. Sometimes due to these corrupted system files, you can encounter the error. SFC is one such tool that not only helps you identify those files, but also fix them. To run it, you can go through the next section where you will find all the necessary steps.

  • Press the Windows Start button and search for ‘cmd’ via the Windows Search option.
  • When the search result appears, right-click on the command prompt to open it with administrator rights. To do that, select the option Run as administrator from the list that appeared.
  • Once Command Prompt opens, type the following command and then hit Enter key to run this utility.

SFC /scannow’

It will take a while to complete the verification procedure of such files in your system. With these steps, you can easily check for damaged system files. Once it completed you should no longer get the error with your Windows Defender. If there were any corrupt files that prevented the Defender from running, this should be fixed.

Final note

If you encounter Windows Defender error code 0x800B0100 on your PC, you can try the methods mentioned in the above section. The methods should be able to successfully fix the error you encountered. We hope that writing has been able to help you fix the error.

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