How to Disable or Enable Windows Defender in Windows 10 - If you're running Windows 10 Home, you won't have access to the Local Group Policy Editor. But you can disable it using Registry Editor.
Press Windows key + R keyboard shortcut to open the Run command, type regedit in the box, and click OK to open the registry.
Now Browse the following path:
HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows Defender
If you don't see DWORD Disable AntiSpyware, right-click on an empty space, select New, and click on DWORD (32-bit) Value.
Name the key DisableAntiSpyware.
Right-click the newly created key, click on modify and set the value from 0 to 1 to turn it off.
If you want to re-enable Windows Defender protection, you only need to follow the simple steps
Open Registry Editor...
Browse the following path:
HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows Defender
Change the value from 1 to 0 to re-enable this feature.
You Can also disable Windows Defender using the Settings app:
If you're only looking to disable Windows Defender temporarily; you can do the following steps:
1) Open Settings from the start menu.
2) Click on Update & security.
3) Click on Windows Defender.
4) Turn off the toggle switch for Real-time protection.
Read More! Windows 10 Start Menu Pro