How to Fix Windows Defender Real-Time Protection Keeps Turning Off

What Causes This?

Windows Defender real-time protection usually turns itself off because another antivirus is installed, a policy or registry setting is forcing Defender to stay disabled, or a security service is not running correctly. It can also happen after malware changes Windows security settings, or after a Windows update leaves Defender components in a broken state. In some cases, “tamper protection” or third-party security tools create conflicts that make the setting refuse to stay on.

Common Symptoms

• Real-time protection switches off again after you turn it on
• Windows Security shows “Virus & threat protection is turned off”
• You see messages saying your device is vulnerable or unprotected
• Defender settings are grayed out or managed by your organization
• Security services fail to start or stop unexpectedly

How to Fix It Manually

1. Check for another antivirus program

   • Press Windows + I to open Settings.
   • Go to Apps > Installed apps.
   • Look for antivirus tools such as Norton, McAfee, Avast, AVG, Bitdefender, or similar.
   • If one is installed, uninstall it, then restart your PC. Windows Defender often disables itself automatically when another antivirus is present.

2. Turn real-time protection back on in Windows Security

   • Press Start, type Windows Security, and open it.
   • Click Virus & threat protection.
   • Under Virus & threat protection settings, click Manage settings.
   • Turn Real-time protection to On.
   • If it switches off again immediately, continue with the next steps.

3. Make sure required Microsoft services are running

   • Press Windows + R, type services.msc, and press Enter.
   • Find Microsoft Defender Antivirus Service.
   • Double-click it and check that Startup type is not disabled.
   • Also check Security Center and Windows Security Service.
   • If any service is stopped, click Start, then click Apply and OK.

4. Check Group Policy if Defender says it is managed

   • Press Windows + R, type gpedit.msc, and press Enter.
     • If this does not open, your edition of Windows may not include Group Policy Editor. Skip to the next step.
   • Go to Computer Configuration > Administrative Templates > Windows Components > Microsoft Defender Antivirus.
   • Double-click Turn off Microsoft Defender Antivirus.
   • Set it to Not Configured or Disabled, then click Apply.
   • Restart your PC and check Windows Security again.

5. Repair system files

   • Right-click Start and choose Terminal (Admin) or Windows PowerShell (Admin).
   • Run this command:

     sfc /scannow

   • When it finishes, run:

     DISM /Online /Cleanup-Image /RestoreHealth

   • Restart your PC after both scans complete.

6. Scan for malware

   • Open Windows Security > Virus & threat protection.
   • Click Scan options.
   • Choose Microsoft Defender Offline scan, then click Scan now.
   • Your PC will restart and scan for threats that may be disabling Defender.

7. Install Windows updates

   • Open Settings > Windows Update.
   • Click Check for updates.
   • Install everything available, including security and platform updates, then restart.

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