There are a few methods, but home users have fewer options due to the lack of a policy editor.
- Start “regedit” from the search or run line
- Goto HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows Defender
- Create a new 32bit Dword called DisableAntiSpyware
- Press Enter
- Modify the DWORD’s value data field to be a hex value of 1
- Click OK
If you check your Windows Defender Settings in Settings, Update & Secruity, Windows Defender, you will now she it off and greyed out