Windows Defender Crashes? How to Fix it?


Microsoft’s default anti-virus, spyware and malware protection, Windows Defender, guards your computer against the execution of potentially unwanted and harmful objects. This system security tool, which is an inbuilt antivirus since Windows 8, may often crash.

Download Diagnostic

You’re just 3 steps away from fixing this problem…

1. Download and install the Diagnostic

2. Run full scan

3. Perform system clean-up & repair

Estimated download time: 10 Seconds


Restart Windows Defender Service

Check whether the Windows Defender service is running or stopped. If the service is not running, restart it using the following command-lines.

  1. Press Windows Key + X, select Command Prompt.
  2. Enter the following commands:
  • net stop WinDefend
  • net start WinDefend
  1. Exit

Perform System File Scan

Using System File Checker, scan for corruption in Windows operating system files and components. Repair and restore the Windows system files as shown below:

  1. Open the Command Prompt again.
  2. Type SFC/ SCANNOW and press ENTER.

Pause & Reactivate Real-Time Protection

Try pausing and re-activating the real-time scan, a mechanism that checks for viruses each time you access a file. Here are the steps to stop on-access scan:

  1. Open the Windows Defender.
  2. Click Settings icon.
  3. Click the Real-Time Protection tab.
  4. Uncheck the box named Turn on real-time protection (Recommend).
  5. Click the Save changes.
  6. Repeat the Steps # 2-3.
  7. Check-up Turn on real-time protection (Recommend), and click Save changes.

Uninstall Third Party Antivirus

Windows Defender may be experiencing conflict with a third party Antivirus installed on your computer. Temporarily uninstall your Antivirus and check whether the problem occurs again.

  1. Right-click the Antivirus icon in the system tray area of your Taskbar.
  2. Select Pause protection.
  3. Confirm the action in the subsequent prompt.
  4. Click Start, and then Settings.
  5. Click System | Apps & Features.
  6. Locate the Antivirus program you’re currently using.
  7. Click the Uninstall button.
  8. Follow the removal instructions on your screen.