Why My Windows Defender Won’t Turn ON?

 Windows Defender Won’t Turn ON

Windows Defender protects your computer from all types of threats. At times, your Windows Defender might refuse to turn on. This happens especially in the case of the Windows 10 computer. Many users have reported the Windows Defender program does not turn on on their Windows PC. We will address the issue in this article. Let us see why Windows Defender won’t turn ON on your Windows 10 computer.

The Reason Behind The Issue

  • A lot of Windows 10 users report that they are unable to turn on Windows Defender because this antivirus program detects that there is another antivirus software running on the computer. However, users confirm that they have removed all the other third-party software from their Windows 10 computers.
  • It is to be noted that there has been a recent explosion of such issues associated with Windows Defender following the Anniversary Update release.
  • Continue reading to find out how to resolve that issue.

Troubleshooting Methods

Method 1 - Utilizing Antivirus-Specific Removal Tool

  • When you uninstall any third-party antivirus program from your computer’s Control Panel, there is a chance that some files will remain undetected. And, this scenario will prevent you from running Windows Defender on your Windows 10 computer.
  • Therefore, you have to use a specific removal tool that is available for the antivirus that you used on your computer, before installing Windows Defender. Added to the antivirus removal tool, you can make use of an uninstaller software. Using such uninstaller software, you can completely remove the antivirus from your computer.
  • NOTE: An uninstaller software is nothing but a special app that has been designed and optimized to remove programs from your computer.
  • Now, continue reading to find out how to fix the Windows Defender won’t turn ON problem on your computer.
  • When you use an uninstaller, it will remove the antivirus from your computer. In addition, the uninstaller will also remove all the files and registry entries that are associated with that antivirus. And, uninstaller programs are pretty much simple and easy to use.
  • So, what you need to do is, uninstall the remnants of the antivirus that you previously installed on your computer. Then, restart your computer. Now, Windows Defender will turn on automatically.
  • If you find that the Windows Defender wont turn on even after removing the antivirus remnants, you need to check if Windows Defender is corrupted. Move on to the next method to do the same.

Method 2 - Performing A Check Of Your System Files

  • You can use the System File Checker tool to see whether Windows Defender is corrupted or not. This tool will also repair the corruption in the system files. Now, carry out the following instructions to do an SFC scan on your Windows 10 computer.
  • On your computer’s keyboard, press the Windows key and the X key. From the displayed options, choose Command Prompt (Admin).
  • In the Command Prompt window that is displayed, type sfc /scannow and press the Enter key.
  • Please wait for the scanning to finish.
  • In case you are unable to run an SFC scan, try using a DISM scan. Follow these steps to do the same.
  • Start the Command Prompt as administrator.
  • In the Command Prompt window that is displayed, type DISM /Online /Cleanup-Image /RestoreHealth and then press the Enter key.
  • Please wait patiently for the DISM scan to get over. It will usually take about 20 minutes or more. Avoid interrupting the scanning.
  • When the scanning is over, check if the issue persists. If the DISM scanning fails to solve the problem, try performing the SFC scan once more. If the problem is not solved, move on to the next method.
  • Continue reading this article to know the last method in fixing your Windows Defender won’t turn ON on issue.

Method 3 - Clean Boot Your Windows 10 Computer

  • In some situations, any third-party apps might interfere with Windows, and your Windows Defender did n't turn on. You can locate the problematic third-party app by doing a Clean Boot. Now, follow these instructions to do a Clean Boot.
  • On your keyboard, press the Windows key and the R key at the same time. The Run dialog box will pop up.
  • In the dialog box, type msconfig. Press the Enter key.
  • The System Configuration window will now pop up. Here, click the Services tab.
  • Deselect the checkbox next to the Hide all Microsoft services option. Then, click on the Disable all button.
  • Now, click the Startup tab and then click on the Open Task Manager button.
  • You will now find a list of startup apps. Right-click the very first entry and choose Disable. Repeat this procedure for all your startup apps.
  • After disabling all the startup apps, return to the System Configuration window and click on the Apply button, followed by the OK button.
  • Restart your computer.
  • Check if the problem persists. This indicates that one of the disabled apps was the reason behind the issue.
  • To zero in on the problematic app, enable the apps one by one or in groups. Do this until you recreate the issue.
  • Finally, disable or uninstall the problematic app.

If the Windows Defender won’t turn ON even now, you can contact our technical experts for more solutions and assistance.


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