How to Resolve Windows Defender Not Activating | 7 Solutions

The main takeaway.

• Windows Defender is crucial for maintaining system security while using the internet or downloading files.
• Unfortunately, there might be instances where Windows Defender fails to activate altogether.
• Let's explore the "Windows Defender not turning on" error in Windows 11/10/8/7, how to resolve it using straightforward methods, and how to utilize a free backup tool - Tips Todo Backup - to safeguard your computer data from viruses or malware.

How to Resolve Issues with Windows Defender Not Opening/Functioning

Let's immediately explore solutions to fix Windows Defender if it's not functioning correctly. Attempt these 7 methods sequentially to determine if the issue is resolved.

1. Fix 1: Enable Real-Time Protection
2. Fix 2: Temporarily Disable Third-party Antivirus Software
3. Fix 3: Restart the Security Center Service
4. Fix 4: Run System File Checker (SFC) Scan
5. Fix 5: Enable Windows Defender via Group Policy
6. Fix 6: Turn on Windows Defender via Registry Editor
7. Fix 7: Update Windows

Solution 1: Enable Real-Time Protection

Windows Defender comes equipped with a real-time protection feature, and if this feature is disabled, you won't be able to open or run the application. Moreover, a significant number of functions are tied to Real-Time protection. Therefore, we need to verify its status and re-enable it.

Step 1. Press Windows + S, search for Settings, and launch it. Next, proceed to Update & Security from the left-hand panel.

Step 2. Open the Windows Security section and click on Virus & Threat Protection.

Step 3. Next, navigate to the Virus & Threat Protection section and click on the Manage Settings link from the available options.

Step 4. In the new window, enable the toggle for Real-Time Protection. Restart your computer to apply the changes.

Solution 2: Temporarily Disable Third-party Antivirus Software

One significant reason for the Defender's malfunctioning is often due to conflicts with third-party antivirus software. To address this issue, we can attempt to temporarily disable the third-party antivirus and see if the application functions properly. Here are the steps to temporarily disable the antivirus: 1. Identify the antivirus software installed on your system, such as Avast, McAfee, Norton, or others. 2. Access the antivirus program's settings or control panel. This is usually done by right-clicking its icon in the system tray (near the clock) or through the Start menu. 3. Look for an option like "Disable," "Pause Protection," "Turn Off," or "Enable Safe Mode." The terminology may vary depending on the antivirus. 4. Select the option to disable the antivirus for a specific duration, like 10-30 minutes. Ensure not to disable it for an extended period to maintain your system's security. 5. Once disabled, restart your computer and check if Windows Defender is working correctly. 6. After verifying the issue, remember to re-enable the third-party antivirus for continued protection. If the problem is resolved after disabling the antivirus, you might need to consider adjusting the settings of the antivirus or uninstalling it in favor of using only Windows Defender.

Note: Not having an active Antivirus program exposes you to external risks. Therefore, if you decide to disable your antivirus, make sure you are aware of the potential dangers involved.

Step 1. Right-click on the empty area on your taskbar and select Task Manager.

Step 2. Maximize the Task Manager window to view its contents in more detail.

Step 3. Click on Start-up in the header menu at the top. Now, locate the antivirus program installed on your device from the listed items.

Step 4. Click on the program to select it, and then click the Disable button at the bottom.

Step 5. Now that you've disabled the app from launching at startup, restart your PC to see if the changes take effect.

If you recall the password for your antivirus program account, uninstall the program to check if it resolves the issue.

Solution 3: Restart the Security Center Service

The Windows operating system employs various services to ensure smooth functioning and task execution. Likewise, Defender utilizes a security service to implement protective measures on your computer. We can attempt to restart this service to check if it resolves the issue.

Step 1. Press the Windows + R keys to open the Run dialog box. Type the services.msc command and press Enter.

Step 2. The Services window will open, and you can locate the Security Center service from the list.

Step 3. Right-click on the service and choose Refresh from the context menu.

Step 4. This action will restart the security service. Now, attempt to check if Windows Defender is activating or not.

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Fix 4: Run SFC Scan

SFC, short for System File Checker, is a utility that scans and repairs Windows system files for errors and corruption. If any of the Windows files are causing Microsoft Defender to malfunction, running an SFC scan can potentially restore the original, functional files.

Step 1. Open Command Prompt (CMD) with administrative privileges.

Step 2. Type the SFC scan command and press the Enter key.

sfc /scannow This command translates to "System File Checker with the scan now option" in English. It is a command used in Windows operating systems to scan and repair corrupted system files.

Now, the SFC scan will commence. This process may take some time, so please wait until the verification reaches 100%. Once completed, close the Command Prompt and check if the unexpected error with Windows Defender has been resolved.

If the SFC scan fails with an error message, you can run the following DISM command to resolve the issue:

DISM /Online /Cleanup-Image /RestoreHealth This command translates to: Deployment Image Servicing and Management (DISM) /Online /Cleanup-Image /RestoreHealth This is a command used in Windows operating systems to repair the system image and restore its health by using the System File Checker (SFC) and Windows Update to fix any corrupted or missing system files.

Fix 5: Enable Windows Defender via Group Policy

The Local Group Policy Editor allows you to modify the files within the operating system. Either accidentally or by another user, the Windows Defender might have been completely disabled through Group Policy. In some instances, even malware can do this. Therefore, let's examine the Group Policy and re-enable the Windows Defender.

Step 1. Press Windows key + S, and type Group Policy. Click on Edit Group Policy from the search results.

Step 2. Next, proceed to the following path to locate Microsoft Defender Antivirus in the Local Group Policy Editor: Computer Configuration → Administrative Templates → Windows Components → Microsoft Defender Antivirus.

Step 3. Double-click on Turn off Microsoft Defender Antivirus to open a new window.

Step 4. Toggle the button next to Not Configured, and then click the Apply button. Restart your computer to check if the Defender Antivirus has started working again.

Solution 6: Enable Windows Defender through Registry Editor

To make changes through the Group Policy Editor, you need to be a Windows 10 business user. However, you can activate Windows Defender using the Windows Registry. Let's explore how to modify the Registry Editor to enable Windows Defender.

Step 1. Press the Windows + R keys on your keyboard to open the Run dialog box.

Step 2. Type regedit and press Enter to open the Registry Editor window.

Step 3. Paste the path in the Navigation pane to open Windows Defender.

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows Defender This is the path to a registry key in Windows. In English, it would be translated as:
HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows Defender

Step 4. Locate the registry entry named DisableAntiSpyware in the list, and then click on it.

Step 5. If you don't see an entry with the name, right-click on any empty space and select New > DWORD (32-bit) Value. Name the entry as DisableAntiSpyware, and then double-click it to open it.

Step 6. Set the Value data to 0, and then click OK. Close the Registry Editor window. Restart your computer to check if you can now open Windows Defender.

< a id="7" name="7">Fix 7: Update Windows

Typically, you can check for updates if the issue pertains to the Windows operating system. If there are any available updates, download them to see if the error is resolved.

Note: It is crucial to back up your system to ensure the safety of your data. Therefore, before proceeding with the update, create a backup of your data for emergency purposes.

Step 1. On Windows 10, go to Settings > Update & Security. On Windows 11, access Settings > Windows Update.

Step 2. Click on Check for updates. The system shows the available updates for the operating system.

Step 3. Install the updates and restart the system to check if the Defender turns back on.

If you encounter a black screen error after updating your Windows, you can seek assistance from the article below.

Translate into English

How to Solve the Windows 10 Black Screen Issue After an Update

The Windows 10 black screen after update issue is one of the most frequent errors encountered by users following a system update. If you're experiencing this problem, this blog is for you, as we've outlined 9 solutions to fix it. Read more >>

How to Protect Your PC's Data from Virus Attacks

As we've discussed, if your Windows Defender isn't activating, your system is vulnerable to external threats. If the defender is malfunctioning and you don't have an active antivirus solution, your data could be at risk from virus or malware attacks. In such situations, the best way to safeguard your PC's data is to back up your system and restore it as necessary. The Todo Backup, a free backup software, can assist you with this task.

It is a dependable backup utility equipped with advanced backup solutions. In addition to backing up your entire system, it enables you to create bootable USB drives as a safeguard against virus or Trojan attacks. You have the flexibility to perform full, incremental, and differential backups, and store them in various locations. Here are some notable features of this backup tool:

• Transfer operating system from one computer to another
• One-click backup & restore options with a user-friendly interface
• Create a system image of Windows on an external hard drive
• Clone a hard drive and image a hard disk with just a few clicks
• Offer 250GB free Cloud storage for backing up files to the Cloud

Aside from safeguarding against virus and malware attacks, Todo Backup tools can ensure the safety of your data in the event of drive failures, physical damage, or unexpected emergencies. Utilize backup software like Todo Backup now to protect your data from potential malware or virus threats.

Step 1. Launch Todo Backup on your computer, and click Create Backup on the home screen. Then, hit the big question mark to select backup contents.

Step 2. To back up your Windows operating system, click "OS" to start the backup task.

Step 3. Your Windows operating system information and all system-related files and partitions will be automatically selected, so you don't need to make any manual selections here. Next, you'll need to choose a location to save the system image backup by clicking on the highlighted area.

Step 4. The backup location can be another local drive on your computer, an external hard drive, a network, cloud, or NAS. Generally, we recommend using an external physical drive or cloud to store your system backup files.

Step 5. If interested, you can access customization settings such as enabling an automatic backup schedule for daily, weekly, monthly, or event-based backups, as well as creating differential and incremental backups by clicking on the Options button. Press "Backup Now" to initiate the Windows system backup process. Once completed, the backup task will be displayed on the left side in a card format.

Why Isn't Windows Defender Turning On?

Windows Defender is failing to activate or launch. Similar to how several default applications can become corrupted over time, the Defender may encounter the same problem due to Windows updates or existing malware infections.

Another common reason is that installing a third-party antivirus can cause conflicts, preventing Microsoft Defender from activating. If you have installed a third-party antivirus such as TotalAV, Norton, or McAfee, it is recommended to disable Windows Defender to ensure smooth operation of the security scans.

Here's a list of the most common reasons why Windows Defender is not starting on your PC:

1. Conflicts between Defender and third-party antivirus software.
2. If the time and date on your computer are not synchronized correctly.
3. Due to an incorrect system configuration on the device.
4. If you have disabled Windows Defender using the Group Policy Editor.
5. Registry Editor modifications are blocking Windows Defender from starting.
6. The Windows Defender service is disabled or not running.

Bottom line.

If you encounter the "Windows Defender not turning on" error, it's crucial to address it immediately to prevent any potential issues. Discover how to fix Windows Defender not working or failing to open in the article and safeguard your data.

The best approach is to back up your system to safeguard your PC from external threats or system crashes. Utilize the reliable and free backup software, Todo Backup, to automate your data backup process. Download and give it a try!

Frequently Asked Questions (FAQs) About Windows Defender Not Activating

Here are some of the most commonly asked FAQs regarding Windows Defender not activating. I hope you find these questions and answers helpful.

1. How do I reinstall Microsoft Defender?

To reinstall Windows Defender, please follow the steps outlined below:

1. Open the Windows Terminal with administrative privileges. 2. Execute the following command to reinstall Microsoft Defender:

Get-AppxPackage Microsoft.SecHealthUI -AllUsers | Reset-AppxPackage

2. Can Windows Defender be permanently disabled?

Yes, although it's challenging, you can still permanently disable Windows Defender.

Edit the Group Policy Editor. Change the Registry Editor settings. Run the below command with CMD.

```shell reg add "HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Microsoft Defender" /v DisableAntiSpyware /t REG_DWORD /d 1 /f ``` This command adds a registry key in Windows to disable Microsoft Defender Antivirus. It creates or modifies the value named "DisableAntiSpyware" under the key "HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Microsoft Defender". The value is set to a DWORD (32-bit) with a data of 1, which disables the antivirus feature. The "/f" flag is used to force the update without prompting for confirmation.

3. Why isn't Windows Defender removing a virus?

There are several reasons why Windows Defender might not remove a virus.

• If your C drive doesn't have sufficient space for the defender to isolate the malware.
• Temporary files, cookies, and application log files restrict the app's functionality.