At times, users can face Windows Defender error code 0x80073b01 when they try to turn it on. This error is mainly caused due to conflict of Windows Defender with some other third-party security software. 

Thus, when this happens, you will face with the error code 0x80073b01 on Windows Defender when you try to activate it on your system. 

Why is Windows Defender Error Code 0x80073b01 Caused

Usually, the Windows Defender error code 0x80073b01 occurs due to its conflict with some other security software. In other cases, it may happen due to a corrupted Windows Defender application or malware attacks on your computer. 

Some other causes of this error are – 

  • Windows Registry Errors 
  • Corrupted or Incomplete installation of security components in Windows OS 
  • Misconfigured Files 
  • Virus infection 
  • Interference from Anti-malware or Anti-spyware applications 

How to Fix Windows Defender Error Code 0x80073b01

Windows Defender error code 0x80073b01 can easily be resolved quickly. However, before jumping to the specific fixes, you can try the following quick fixes to see if it can resolve this error. 

  • Run a full system scan of your computer 
  • Disable or Uninstall third-party antivirus software 
  • Remove anti-malware, anti-spyware, and other such applications 
  • Update to the latest version of Windows 

Solution 1 – Fix Windows Registry 

Windows Registry is an important database that contains software settings. It can misconfigure an application if these settings are changed or corrupted. Therefore, Windows Defender error code 0x80073b01 could occur due to such registry errors. 

Usually, this particular error is caused due to ‘msseces.exe’ entry in the registry. Thus, you have to delete this entry to fix the error. You can do this by following the steps below. 

  1. Press the Windows logo button and the letter ‘R’ at the same time. Type ‘notepad’ and press enter. 
  2. Here, copy and paste the following statements – 

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\Current Version\Image File Execution Options]


[HKEY_CURRENT_USER\Software\Microsoft\Windows\Current Version\Policies\Explorer\DisallowRun]


  1. Next, click on File and select Save As. Choose ‘All Files’ under Save as Type.
  2. Name this file ‘delete.reg’ and save it in your desired directory. 
  3. Close the notepad. Open the Windows File Explorer and locate this file. 
  4. Right-click and open this file as an Administrator’. Click on ‘Yes’ when a prompt appears. 
  5. Lastly, restart your computer for the changes to take place.  

Solution 2 – Run System File Checker 

Microsoft has incorporated a built-in system file checker that can automatically scan and fix corrupted system files. You can easily execute this program with a simple command line. 

Follow these steps to run the System File Checker. 

  1. Click on the Search button located right next to the Start button. Type ‘cmd’. 
  2. Right-click on ‘Command Prompt’ and Run the program as an Administrator. 
  3. Here, type ‘sfc /scannow’ and press enter. 
  4. Wait for the command to be executed and then close the Command Prompt window. 
  5. Lastly, restart your computer. 

Solution 3 – Run Microsoft DISM Tool 

The Deployment Image Servicing and Management is a utility tool that can automatically scan and fix Windows image errors. 

Furthermore, it can be easily executed like the system file checker. Follow these steps to run the Microsoft DISM tool.

  1. Click on the Search button and then type ‘cmd’. 
  2. Right-click on the topmost result and Run the application as an Administrator. In the Command Prompt window that opens, type “DISM.exe /Online /Cleanup-image /Restorehealth” without the quotes. 
  3. Next, press Enter and wait for the command to be executed. 
  4. Lastly, restart your computer.