FIX: Windows Defender won’t turn on Windows 10

• Windows Defender’s name does a pretty good job at pointing out its purpose, which is to defend your computer against all kinds of threats out there.
• Usually, Microsoft’s build-in protection tool quietly runs its MsMpEng.exe process in the background without you even noticing it, but sometimes it might find itself in need of a little TLC. For instance, you might deal with a case of Windows Defender not turning on at all in Windows 10. Check out our solutions to promptly fix this in the article below.
• There are many other issues that may come your way in connection to Microsoft’s antivirus, but we have covered them all. Feel free to explore the Windows Defender errors section to learn everything there is to know on this topic.
• Do not forget to bookmark the Windows 10 errors page for future reference and guidance as well.

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This isn’t the first time users have reported they can’t turn on Windows Defender, but we can’t help but notice there has been an explosion of issues surrounding Windows 10‘s built-in antivirus following the Anniversary Update release.

Windows Defender is a built-in antivirus in Windows 10, and it provides solid protection for the most part. However, many users reported that Windows Defender won’t turn on on their PC, and this could be a problem.

Speaking of problems, these are some of the common issues that users reported:

• Can’t turn on Windows Defender Windows 8 – This problem can also appear on Windows 8, but you should be able to fix it using one of our solutions.
• Windows Defender won’t open – Many users claim that Windows Defender won’t open on their PC. If that’s the case, remove all third-party antivirus tools from your PC. In addition, be sure to remove all files and registry entries associated with your antivirus.
• Windows Defender is turned off by group policy – Sometimes Windows Defender won’t run since it’s disabled from Group Policy. However, you can easily fix that with one of our solutions.
• Windows Defender won’t turn on unexpected error – In some cases, you might get an error message while trying to start Windows Defender. If that happens, try performing SFC and DISM scans and check if that solves your issue.
• Windows Defender won’t turn on after uninstalling Avast, Bitdefender, McAfee, AVG – Sometimes Windows Defender won’t start even after you uninstall your antivirus. To fix that issue, be sure to use the dedicated removal tool to remove all leftover files and registry entries associated with your antivirus.
• Windows Defender won’t turn on Windows 10 Spybot – Many Windows 10 users reported this issue with Spybot application. To fix the issue, be sure to remove Spybot completely from your PC and check if that solves the problem.
• Windows Defender won’t open, run, work, enable, start – There are many problems with Windows Defender that can occur, and if you have issues running Windows Defender, feel free to try some of our solutions.

What can I do if Windows Defender won’t turn on in Windows 10?

1) Use antivirus specific removal tools

When you uninstall third-party antivirus solutions using the Uninstall option from the Control Panel, it’s possible that some files remain undetected and this prevents you from running Windows Defender.

Check out this list of antivirus removal tools, and run the tool available for the antivirus you used before installing Windows Defender.

In addition to these tools, you can also use uninstaller software to completely remove your antivirus from your PC. If you’re not familiar, uninstaller software is a special application optimized for removing programs.

The uninstaller will remove the selected application, but it will also remove all files and registry entries associated with that application. As a result, the selected application will be completely removed and it will be as if the application was never installed.

As for uninstaller software, there are many great tools, but the best are IOBit Uninstaller and Revo Uninstaller. All these tools are simple to use, so you should be able to remove your antivirus with ease.

Uninstall the remnants of your previous antivirus, restart your computer and Windows Defender should be automatically enabled.

2) Check your system files

The System File Checker tool repairs corruption in system files. Use this tool to verify whether Windows Defender is corrupted or not. To perform an SFC scan, do the following:

1. Press Windows Key + X to open Win + X menu. Now select Command Prompt (Admin) or PowerShell (Admin) from the menu.
   
2. Type the command sfc /scannow > hit ENTER > wait for the scan to complete.
   

If you can’t run an SFC scan or if SFC can’t fix the problem, you might want to try using a DISM scan instead. To do that, just follow these steps:

1. Start Command Prompt as administrator.
2. When Command Prompt opens, enter DISM /Online /Cleanup-Image /RestoreHealth and press Enter to run the command.
   
3. DISM scan will now start. This scan can take up to 20 minutes or more, so don’t interrupt it.

Once the scan is finished, check if the problem still persists. If you were unable to run an SFC scan before, or if the DISM scan doesn’t solve your problem, repeat the SFC scan again and check if that solves the issue.

If you’re having trouble accessing Command Prompt as an admin, then you better take a closer look on this guide.

Turn on Windows Defender to access company resources

Organizations want to ensure that devices accessing their resources are secured so they may require you to use Windows Defender. Windows Defender is an antivirus software that’s included in Windows and can help protect your device from viruses and other malware and threats.

This article describe how to update your device settings to meet your organization’s antivirus requirements and resolve access problems.

Turn on Windows Defender

Complete the following steps to turn on Windows Defender on your device.

1. Select the Start menu.
2. In the search bar, type group policy. Then select Edit group policy from the listed results. The Local Group Policy Editor will open.
3. Select Computer Configuration >Administrative Templates >Windows Components >Windows Defender Antivirus.
4. Scroll to the bottom of the list and select Turn off Windows Defender Antivirus.
5. Select Disabled or Not configured. It might feel counter-intuitive to select these options because the names suggest that you’re turning Windows Defender off. Don’t worry, these options actually ensure that it’s turned on.
6. Select Apply >OK.

Turn on real-time and cloud-delivered protection

Complete the following steps to turn on real-time and cloud-delivered protection. Together, these antivirus features protect you against spyware and can deliver fixes for malware issues via the cloud.

1. Select the Start menu.
2. In the search bar, type Windows Security. Select the matching result.
3. Select Virus & threat protection.
4. Under Virus & threat protection settings, select Manage settings.
5. Flip each switch under Real-time protection and Cloud-delivered protection to turn them on.

If you don’t see these options on your screen, they may be hidden. Complete the following steps to make them visible.

1. Select the Start menu.
2. In the search bar, type group policy. Then select Edit group policy from the listed results. The Local Group Policy Editor will open.
3. Select Computer Configuration >Administrative Templates >Windows Components >Windows Security >Virus and threat protection.
4. Select Hide the Virus and threat protection area.
5. Select Disabled >Apply >OK.

Update your antivirus definitions

Complete the following steps to update your antivirus definitions.

1. Select the Start menu.
2. In the search bar, type Windows Security. Select the matching result.
3. Select Virus & threat protection.
4. Under Virus & threat protection updates, select Check for updates. If you don’t see this option on your screen, complete the first set of steps in Turn on Real-time Protection. Then try checking for updates again.

Next steps

Still need help? Contact your company support. For their contact information, check the Company Portal website.

Check if windows defender installed

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• How to Find the Microsoft Defender Version Installed in Windows 10

How to Find the Microsoft Defender Version Installed in Windows 10

Lawrence Abrams

• September 18, 2019
• Read 74,349 times

There are times when it is important to determine what version of Microsoft Defender is currently installed in Windows 10 so you can diagnose a problem or determine if you have the latest version installed.

Unfortunately, Microsoft does not make it very clear how to find this information. This tutorial aims to clear up that confusion.

To find the version number for the installed Microsoft Defender in Windows 10, please follow these steps:

From the Start Menu, search for Windows Security and click on the result when it appears as shown below.

For most users, the Antimalware Client version is what you are looking for as it will indicate the overall version for Microsoft Defender installed in Windows.

Users who read this also read:

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How to Enable the Windows 10 Tamper Protection Security Feature

With the release of the Windows 10 May 2019 Update, Microsoft introduced a new security feature called Tamper Protection that protects security settings for Windows Defender antivirus from being disabled by malware or third-party programs.

Fix a Missing api-ms-win-crt-runtime-l1-1-0.dll DLL in Windows

If you try to run a program and receive an error stating that the api-ms-win-crt-runtime-l1-1-0.dll DLL is missing from your computer, you can use this guide to restore the missing DLL so that you program works again.

How to Use Windows Defender to Scan a Folder for Malware

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Windows Defender not working [FULL FIX]

• There are instances when a computer is not protected because Windows Defender won’t turn on Windows.
• If Windows Defender real-time protection won’t turn on Windows 10, then you should check its settings.
• Sometimes, the date and time settings are the reason why Windows Defender won’t turn on.
• Using dedicated software solves the failure of the Windows Defender antivirus to turn on in Windows 10.

Often we hear people complaining that they cannot turn on Windows Defender in Windows 10, so today we’ve decided to share with you a few tips on how to fix this issue.

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Windows Defender won’t start

Here are some examples of how this issue may manifest itself:

• Can’t turn on Windows Defender Windows 10 Group Policy
  • If you get this error, check out our article about Group Policy Editor and Windows Defender.
• Can’t turn off Windows Defender Windows 10
  • If you want to switch to another antivirus program, this problem might prevent you from turning off Windows Defender.
• Windows Defender real-time protection handled by another av program
  • Windows Defender and another antivirus program don’t go along (see below).

There are a few possible scenarios for this problem, and we’ll cover most of them in this article.

What to do if Windows Defender is not working in Windows 10

1. Enable real-time protection

1. Press the Windows key + Q key on the keyboard to bring up the charms search.
2. Type Windows Defender in the search box and then press Enter.
3. Head over to the Settings and check Turn on real time protection.
   

Windows Defender is designed to turn itself off if it detects any other third-party antivirus software. Windows is designed to detect any installed antivirus software, and certain issues can occur if you have two or more antivirus software installed.

These issues include conflicts between antivirus software that can manifest as frequent freezing, crashing to applications, etc.

Since this is a common problem, in order to avoid any conflicts, Windows Defender will turn itself off if Windows detects any other security program.

In addition, if this security software has a Firewall, Windows Firewall will also turn itself off.

This means that if you want Windows Defender to work, you’ll have to choose between it and the third-party antivirus software.

Often users are not aware of whether security software is installed or not because when you buy a new laptop in most cases it comes with a trial version of antivirus software such as Norton, McAfee etc.

When you install applications like Flash or Java it might prompt you to uninstall the free security scanner, and that can cause some problems.

Therefore it’s best to search your PC if you’re not sure whether security software is installed or not. Once you remove it, you might need to manually turn it back on using these steps:

2. Change date and time

Another cause for Windows Defender to not work properly is incorrect time and date on Windows 10.

In order to fix this, you need to check your time and date and set it to the correct value before trying to turn Windows Defender back on.

We know that this might sound strange, but most of the Windows system functions are dependent on time and date, therefore an incorrect date or time could trigger abnormal behavior in your Windows OS.

3. Use professional software for protection

Windows Defender is a useful feature for your operating system, but if it doesn’t function properly, you can try profesionnal software. This program is constantly improved through updates by its developer so that it will detect and repair the latest malware that will appear.

Try out the ultimate cybersecurity package that will provide you with online safety. This software was created for users that want full protection against online threats.

This means you will also benefit from extra theft protection and a user-friendly password management feature. Feel free to install and use on any Windows, Android, Mac or Linux device, as it is compatible with all four operating systems.

Keep your digital identity under protection from unauthorized third-parties with this software’s advanced antivirus technology. This application will also offer efficient protection of your confidential data from phishing and ransomware.

If you desire more privacy for your files, then you can choose to encrypt them and removable media too. This is professional software that keeps you organized with good password management, by storing and organizing them.

Eset Smart Security Premium

4. Update Windows

1. Go to Start, select Settings, and choose Update & Security.
2. Navigate to Windows Update, and then select Check for updates.

Make sure that you keep your Windows up to date using Windows Update since this can cause some problems with Windows Defender. When it comes to any security software, make sure that you update it frequently.

We suggest that you perform a full Windows Update, then open Windows Defender and run an update from there as well.

If you can’t open the Setting app, we have a special article for how to solve the issue.

5. Change Proxy Server

1. Press Windows key + X and select Command Prompt (Admin).
2. Type in one of the following: NETSH WINHTTP SET PROXY 1.1.1.1:8080 or NETSH WINHTTP SET PROXY MYPROXY.NET:8080
3. Reboot the system and see if it works.

These three are most common scenarios that can cause problems with Windows Defender, but there are some other not so common scenarios that can cause problems as well.

For example, incorrect Zone settings in Internet Explorer can cause problems, but you can easily fix this by resetting Internet Explorer to factory settings.

Bear in mind that if you are using a Proxy server, Windows Defender will not be able to update. If that’s the case, you’ll need to make some minor tweaks to your Proxy server.

If you’re having trouble accessing Command Prompt as an admin, then you can read one of our guides.

6. Disable third-party antivirus

Windows Defender doesn’t get along with third-party antivirus programs. Just like any two antivirus programs don’t work well with each other.

So, if you want Windows Defender to be your primary security option, make sure to disable any third-party antivirus programs you have installed on your computer.

7. Run the SFC scan

1. Go to Search, type cmd, and open Command Prompt as Administrator.
2. Enter the following line and press Enter: sfc/scannow
3. Wait for the process to finish.
4. Restart your computer.

This simple solution shows how to run the SFC scan in Windows 10.

8. Run DISM

1. Go to Search, type cmd, and open Command Prompt as Administrator.
2. Enter the following command on the command line:
   • DISM.exe /Online /Cleanup-image /Restorehealth
     
3. In case the DISM can’t obtain files online, try using your installation USB or DVD. Insert media and type following command:
   • DISM.exe /Online /Cleanup-Image /RestoreHealth /Source:C:RepairSourceWindows /LimitAccess
4. Make sure to replace the following path of your DVD or USB: C:/Repair/Source/Windows

9. Reset the Security Center service

1. Go to Search, type services.msc , and open Services.
2. Find the Security Center service.
3. Right-click the Security Center service, and go to Reset.
4. Restart your computer.

And finally, if none of the solutions from above worked, we’ll try resetting the Security Center service. Hopefully, Windows Defender will start working after that.

That’s about it, we hope at least one of these solutions helped you resolve your problems with Windows Defender. If you have any comments, questions or suggestions, just let us know in the comments down below.