Microsoft Defender is a built-in security application that gives your system real-time protection against malware, viruses, and spyware that can affect your web browsing, emails, applications, and more. However, sometimes you may see Microsoft Defender error: 0x80073b01 on your Windows 10 PC while trying to launch the application. The error prevents the application from starting.
You may not be able to find Windows Defender in Control Panel, or you may receive notifications that it is running or you may receive update messages. But when you try to start it, it doesn't. The error code: 0x80073b01 indicates that there is a conflict between the Microsoft Defender application and other security software on the system. The error can also appear if there is a damaged file that could block it.
While you can try to fix it using other security software or a recovery application, they probably won't help. However, we have a couple of solutions for this problem. Let's see how to fix it.
Method 1: Check if the Windows Defender service is running
Step 1: Go to Windows icon (Home) at the bottom left of the desktop and type Services.
Step 2: Left click on the result to open the file Supervisor window.
Now go to the right side of the window and below Nomi, to locate Windows Defender Firewall.
Step 3: Check if the State è Running and Start type è Automatic.
Step 4: It's his State It is showing Arrested and Start type like Manual, or any of them, right-click the file Windows Defender service and select Property give the menu answer.
Step 5: Now in Property dialog box below the file general tab, go to Start type section and set the field to Automaticand under the Status of the service section, click Home (if applicable) to be sure Status of the service è Running.
print To apply and so ok to save changes and exit.
Step 6: Once done, go back to the file Services window and find:
- Windows Defender Advanced Threat Protection,
- Microsoft Defender Antivirus Network Inspection Service,
- Microsoft Defender Antivirus Service.
Now select them one by one, right click on them to select them Property in the context menu and set the startup type in each of them to Manual.
Also, make sure that the Status of the service è Running for all of them. If not, press the button Home button to start the services.
Now go back and try to launch the Windows Defender app and it should open now. If you still get the error then follow the second method.
Method 2: Re-register the Windows Defender DLL
Step 1: Navigate to Home at the desk and type Symbol of the system in the search field.
Step 2: Right-click on the result and select Run as administrator in the context menu to open the file Symbol of the system in administrator mode.
Step 3: A Symbol of the system window, run the following command one by one and press Log in after each command.
regsvr32 wuaueng.dll regsvr32 wucltui.dll regsvr32 softpub.dll regsvr32 wintrust.dll regsvr32 initpki.dll regsvr32 wups.dll regsvr32 wuweb.dll regsvr32 atl.dll regsvr32 mssip32.dll
These commands will re-register each of the files DLLs in Windows Defender record.
Now restart your PC and try to open the Windows Defender application. It should work fine now. But, if the problem persists, try the third method.
Method 3: running the SFC / Scannow command
Step 1: press the Windows key + X together on the keyboard to open the context menu.
Step 2: In the context menu, select Symbol of the system (Administration) Open Symbol of the system in administrator mode.
Step 3: Now, in the Command Prompt window (admin mode), run the following command and hit Enter:
SFC / scannow
This is the System File Checker command and the process takes some time to complete, so please wait patiently and once done it will show if any damage is found. Repair and restore damaged files immediately.
Restart your computer and the dll files will be replaced with the new ones. You can now run your Windows Defender and there should be no problems.
Alternatively, you can also try the fourth method.
Method 4: removing a third-party antivirus program
As discussed at the beginning, third-party antivirus software is often a major cause of the conflict with the Windows Defender application, and thus you will see Microsoft Defender error: 0x80073b01 on your Windows 10 PC. In such cases, you will need to uninstall the third-party antivirus program.
Step 1: Navigate to Home at the bottom left of the desktop and type Control Panel.
Step 2: Now, left click on the top of the result to open the file Home control panel window.
Step 3: A Control Panel Start window, go to Seen from field at the top right of the screen. Then set the field to Category by selecting from the drop-down menu next to it.
Then scroll down and under Programs section, click to open Uninstall a program.
Step 4: Now under the Uninstall or change a program , find the third-party antivirus software from the list (which you recently installed) and click Uninstall on the top.
That's all. Follow the steps above and you should no longer see the Windows Defender error. You can now open the Windows Defender application.