Although Windows Defender can be disabled until the next restart in Settings, you can prevent it from starting on its own without your permission in Windows Registry Editor. Keep in mind that turning off Windows Defender will expose your computer to security risks. Additionally, changing Registry Editor other than with the settings described in this article can damage your computer to the point of making it unusable.
Steps
Method 1 of 2: Turn off Windows Defender

Step 1. Open the Start menu

Click on the Windows logo at the bottom left of the screen to open the menu To start up.

Step 2. Open settings

Click on the gear icon at the bottom left of the menu To start up. The window of Settings will then be displayed.

Step 3. Click

Update and security.
It is the last option in the bottom row in the window of Settings.

Step 4. Click Windows Security
The tab is at the top of the left column of the window.

Step 5. Click Virus and Threat Protection
This is the first option under the heading Protection zones in the middle of the page. This will open the Windows Defender window.

Step 6. Click Windows Defender Antivirus Options
You will find the link in the middle of the page.

Step 7. Shut down Windows Defender
You can turn off Windows Defender by clicking on the blue slider

located under Periodic analysis, then click Yes to confirm. This will stop Windows Defender's real-time protection.
- You can also turn off Windows Defender's cloud-based protection by clicking on the blue slider marked Enabled, located under the heading Cloud protection, then clicking on Yes to confirm.
- Windows Defender will launch on its own the next time you restart your computer.
Method 2 of 2: Disable Windows Defender

Step 1. Click Start

Click on the Windows logo in the lower left corner of the screen. This will open the Start menu.

Step 2. Open Registry Editor
This program allows you to modify the internal options of your computer. To open it, follow this procedure:
- type regedit;
- click on the blue icon regedit at the top of the menu To start up;
- click on Yes when prompted.

Step 3. Open the Windows Defender folder
To get to the Windows Defender folder, you need to expand all required folders in the left column of theRegistry Editor. To do this, follow this procedure:
- expand the "HKEY_LOCAL_MACHINE" folder by double-clicking (you can skip this step, if it is already expanded);
- expand the folder SOFTWARE;
- go down and expand the folder Policies;
- expand the folder Microsoft;
- click once on the folder Windows Defender.

Step 4. Display the menu
Right click on the folder Windows Defender, a drop-down menu should appear.
- If your mouse does not have a button for right click, press the right side of your mouse or click it with two fingers.
- If your computer has a trackpad, instead of the mouse, tap it with two fingers or press the lower right corner.

Step 5. Select New
The link is at the top of the drop-down menu. Selecting it will bring up a popup menu.

Step 6. Click 32-bit DWORD Value
This option can be found in the menu that has just appeared. By clicking on it, a blue and white icon will appear in the window Windows Defender, on the right side of the page.

Step 7. Name the file
Give it for name DisableAntiSpyware. When the DWORD file appears, type DisableAntiSpyware, then press Enter.

Step 8. Open the file
Double click on the DWORD file DisableAntiSpyware. A popup window will then appear.

Step 9. Activate the file
Replace the number in Value data by 1. This will activate the DWORD value.

Step 10. Click OK
The button is at the bottom of the window.

Step 11. Restart your computer
Click on To start up

, then On / Off

and select To restart in the menu that appears. When your computer restarts, Windows Defender will be disabled.

Step 12. Reactivate Windows Defender
If you decide to reactivate Windows Defender, you will have to change the value again.
- Return to the folder Windows Defender in L' Registry Editor.
- Click once on the folder Windows Defender.
- Open the value editor for DisableAntiSpyware by double-clicking on it.
- Change the value from 1 to 0.
- Click on OK, and then restart your computer.
- You can clear the DisableAntiSpyware value if you don't want to reuse it.