Cannot Turn On Windows Defender In Windows 10


Why won’t Windows Defender turn on? This is a typical issue. Applications with antivirus protection are necessary if you want to take up the internet safely. You are susceptible to several assaults using a private network or public WiFi. If Windows 10’s built-in antivirus cannot turn on Windows defender in windows 10, that is a major warning sign. All Windows 10 systems come pre-installed with Windows Defender. It is available to safeguard against online dangers, including malware, hackers, and others.

Windows Defender will not turn on Windows 10 for a variety of reasons. Including older versions of Windows 10, an incorrect time and date setting, additional security software, and a disabled Windows Defender.

Read this article to discover all the potential causes and the best fixes. If your system cannot turn on Windows defender in windows 10. We will lead the way for you all in solving the issue.


Most of the typical reasons why you cannot turn on windows Defender in windows 10 are as follows:

windows defender

  • You have installed additional security software that prevents Defender from working properly.
  • Your PC’s dates and times need to be aligned or corrected.
  • You may be using an outdated version of Windows.
  • On your device, a configuration problem has occurred.
  • Group Policy has Windows Defender turned off or disabled.
  • A Registry change is hindering the opening of Windows Defender.
  • You have disabled the Windows Defender on your PC.
  • Your machine has a malware infection.

Let us look at what you could do to resolve these problems and get Windows Defender back. The most recent Windows 10 was taken up to build the instructions below.

See Also: 3 Ways To Fix GDI+ Window Preventing To Shutdown

How to start Windows Defender in Windows 10

If you think that the built-in antivirus isn’t working properly, to correct the issues listed below, use the methods:

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Method 1: Activate the real-time protection

It is conceivable that your device’s Windows Defender real-time prevention has been disabled. The software may appear to be failing to open due to this. Additionally, it disables a sizable portion of Defender’s functions, which is not advised. The methods to activate real-time security on Windows 10 are listed below.

1. To open the Start menu, choose the Windows symbol in the lower left of your PC’s screen. Alternatively, press Windows + I to access Settings.


2. On the Update & Security tile, click. The majority of your security tab is located here. Click on Virus & threat defense after switching to the Windows Security tab.

click on virus & threat defense

3. To begin, select the link “Manage settings” from the rubric “Virus & threat protection settings.”

security tab

4. You will get to a specific page. To activate Windows Defender, click the Real-time security toggle here.real-time security

See Also: Fix Windows 10 Slow Shutdown Error

Method 2: Restoring corrupted system files 

Your operating system may experience severe issues due to corrupt system files. Through the SFC scan, defective system files can be found and fixed.

restoring corrupted system files 

Windows 10 has a built-in utility called System File Checker (SFC) that can assist with troubleshooting. It can automatically identify damaged system files and fix them so that they function correctly. The SFC scan can help to resolve several issues.

1. Tapping the magnifying glass emblem in the taskbar can get you to the search area. Additionally, you can access it by pressing Windows + S on your keyboard.


2. Search for Command Prompt there. Right-click it when you find it in the results and select “Run as Administrator.”

run as administrator

3. To grant the app administrator permissions upon launch. Click Yes when the User Account Control (UAC) prompts you to let you do so.


5. To run the following command, enter the text after typing it: “sfc/scan.”

Wait as the System File Checker analyzes your computer if you discover any discrepancies. The software will try to fix any related problems and restore crucial system data.

See also: Use the System File Checker tool

Method 3: Change Your Device’s Time and Date 

According to some users, having the wrong time and date may result in some bizarre issues in Windows 10. When Windows 10 Defender does not turn on, try correcting this.

1. To get the Start menu, tap on the Windows symbol on the left downward of your screen. Alternatively, press Windows + I to access Settings.


2. A new window ought to appear. Choose the Time and Language section from here.

change your device's time and date 

3. Switch between the automated time setting and automatic time zone selection settings. Your times and dates will be updated in Windows 10 to reflect your local time.

change your device's time and date 

4. Go to the Region tab next. Choose the nation or state you are presently in under Country or area. For the modifications to take effect, you must have internet access.

Check to verify whether Windows Defender can launch after restarting your machine.

Method 4: Get yourself the newest version of Windows 10

Try to update your device to the most recent Windows 10 if none of the above options seems effective. It can also close security gaps, correct problems, and add new functionality. How to upgrade to Windows 10 is as follows:

get yourself the newest version of windows 10

1. To get the Start menu, tap on the Windows symbol on the left downward of your screen. Alternatively, press Windows + I to access Settings.

access setting

2. On the Update & Security tile, click. You will find most of your Windows Update options here, and you can also select the frequency of updates.

update and security

3. Keep the Windows Update tab on its default page. After selecting the Check for Updates option, let Windows 10 search for the available updates.

window update

4. Click the View all optional updates link to view and install any already displayed updates.

view all options

5. If it shows an upgrade one, select Install and waits while Windows 10 downloads and applies the required updates.

download and install

See Also: Fix Windows 10 Can’t Connect To This Network

Frequently Asked Questions

Why am I unable to activate Windows Defender in Windows 10?

The Windows system may have a lot of third-party programs operating in the background if you start it in regular startup mode. These programs may interfere with Windows and lead to software conflicts. As a result, you cannot turn Windows Defender on.

Is Windows Defender turned on by default?

The default installed antivirus software is Windows Defender. Consequently, its default setting is frequently 'on.' Windows Defender may switch on automatically when your computer is inactive or when there is a threat from external viruses because the default setting is 'on.'

Is Windows Defender installable manually?

Two methods are obtainable for manually installing. One is Windows Defender and second is Standard technique via Windows PowerShell.

Windows 10 already has Windows Defender installed, right?

Windows Security, which comes with Microsoft Defender Antivirus, is a built-in security feature of Windows 10. Microsoft Defender Antivirus will instantly deactivate if you have another antivirus program installed and running.


We hope the preceding instructions answer why you cannot turn on windows defender in windows 10. We have listed four effective ways to repair Defender-related issues with your device or enable Windows defender.

Now that you have a powerful antivirus program installed on your PC. You can utilize its advantages like browsing with the assurance that you are safe online and offline.