Open Start
Type Windows Security
Open Windows Security
Click Virus & threat protection
Click Manage settings under Virus & threat protection settings
Turn Real-time protection on or off
Open Start
Type Group Policy Editor
Open Edit group policy
Go to Computer Configuration
Go to Administrative Templates
Go to Windows Components
Go to Microsoft Defender Antivirus
Open Turn off Microsoft Defender Antivirus
Set it to Enabled to turn Defender off
Set it to Disabled or Not Configured to turn Defender on
Open Start
Type Registry Editor
Open Registry Editor
Go to HKEY_LOCAL_MACHINESOFTWAREPoliciesMicrosoftWindows Defender
Create or edit DisableAntiSpyware
Set the value to 1 to turn Defender off
Set the value to 0 or delete it to turn Defender on
Open Start
Type Services
Open Services
Find Microsoft Defender Antivirus Service
Right-click it
Click Start to turn it on
Click Stop to turn it off
Open Start
Type Windows Security
Open Windows Security
Click Virus & threat protection
Click Manage settings
Turn Tamper Protection on or off if needed