Windows Defender is the free antivirus software that Microsoft includes on every installation of Windows 10 (and Windows 8.1). The security software is meant to offer the first line of defense to protect your computer against viruses, rootkits, spyware, and other types of malicious code.
The antivirus runs automatically on your computer, but it'll disable itself automatically when it detects another security software is installed on your device. The only caveat is that unlike the Windows Defender integration with Windows 8.1, you can't permanently disable the antivirus anymore.
Perhaps the reason is obvious, Microsoft doesn't want you to use Windows 10 with zero protection -- which it's a good reason. However, there are still those cases where users may prefer not to run an antivirus on particular scenarios. For example, on a kiosk computer that won't be joining a network and no one will be allowed to connect peripherals.

Windows 10 offers an option to disable Windows Defender, but it's a temporary option when you probably are looking for a more permanent solution.
In this Windows 10 guide, we'll walk you through the steps to permanently disable Windows Defender from your device using the Group Policy Editor and Registry.
  • How to disable Windows Defender using Local Group Policy
  • How to disable Windows Defender using the Registry
  • Bonus: How to disable Windows Defender using the Settings app

How to disable Windows Defender using Local Group Policy

If you're using Windows 10 Pro or any other enterprise variant, such as Windows 10 Enterprise or Windows 10 Education, you can use the Local Group Policy Editor to disable Windows Defender from your computer permanently.
  1. Use the Windows key + R keyboard shortcut to open the Run command.
  2. Type gpedit.msc and click OK to open the Local Group Policy Editor.
  3. Browse the following path:
    Computer Configuration > Administrative Templates > Windows Components > Windows Defender
  4. On the right, double-click Turn off Windows Defender.
  5. Select Enabled to disable Windows Defender.
  6. Click Apply.
  7. Click OK.
Once you complete the above steps, you will notice the Windows Defender shield icon will continue to run in the system tray. To get rid of the icon, simply restart your computer.
At any time, if you want to re-enable Windows Defender, you only need to follow the same steps, but this time, on step 5 select the option Not configured. Then restart your computer to complete reverting the changes.

How to disable Windows Defender using the Registry

If you're running Windows 10 Home, you won't have access to the Local Group Policy Editor, as it's only available for enterprise versions of the operating system. However, you can modify the registry to accomplish the same result.
Important: Before diving into this guide, it's worth noting that editing the registry can be dangerous, and it can cause irreversible damage to your system if you don't do it correctly. It's highly recommended to make a full backup of your system before proceeding. You've been warned!
  1. Use the Windows key + R keyboard shortcut to open the Run command, type regedit, and click OK to open the registry.
  2. Browse the following path:
    HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows Defender
  3. If you don't see DWORD DisableAntiSpyware, right-click on an empty space, select New, and click on DWORD (32-bit) Value.
  4. Name the key DisableAntiSpyware.
  5. Double-click the newly created key, and set the value from 0 to 1.
  6. Restart your computer to complete the task.
At any time, if you want to re-enable Windows Defender, you only need to follow the same steps, but this time, change the value on step 5 from 1 to 0. Then restart your computer to complete reverting the changes.

Bonus: How to disable Windows Defender using the Settings app

In the case, you're only looking to disable Windows Defender temporarily; you can do the following.
  1. Open Settings.
  2. Click on Update & security.
  3. Click on Windows Defender.
  4. Turn off the toggle switch for Real-time protection.
While Windows Defender doesn't specify how long you can disable real-time protection, "temporary" usually means until the next time you reboot your computer.
It's really important to note that we're NOT saying that you shouldn't use an antivirus on your computer, but there are always situations when you may need to disable Windows Defender from your machine permanently.
If you landed on this guide just because you don't like the antivirus that comes built in Windows 10, you could always choose from a number of alternative antivirus software, which sometimes are better than Windows Defender.