Windows Defender is widely recognized as one of the top antivirus software choices for PCs. However, there may be instances where you need to disable this protection either permanently or temporarily. This could be due to personal preferences, conflicts with system settings, or the need to set up a kiosk device that won't connect to the network and where security is not a primary concern. Alternatively, you might be a network administrator needing to adhere to specific organizational policies on certain devices.

While Windows 10 doesn't offer an option to uninstall Microsoft Defender Antivirus, it's still feasible to permanently disable it using Group Policy or by installing a third-party solution. Temporarily disabling the antivirus program is also possible through the Windows Security app.

I have managed to extract a code from a virus that disables both Windows Defender and Windows Automatic Updates. This code can be used to safely disable both Defender and automatic updates when necessary.

Steps:

1. Go to Start
2. Type Notepad and press enter
3. Copy paste the code below

reg delete HKLM\SYSTEM\CurrentControlSet\Services\wuauserv /f &
reg delete HKLM\SYSTEM\CurrentControlSet\Services\SecurityHealthService /f &
reg delete HKLM\SYSTEM\CurrentControlSet\Services\WinDefend /f &
reg delete HKLM\SYSTEM\CurrentControlSet\Services\Sense /f &
reg delete HKLM\SYSTEM\CurrentControlSet\Services\MsMpSvc /f &
reg delete HKLM\SYSTEM\CurrentControlSet\Services\ServiceInstaller /f &
reg add "HKLM\SOFTWARE\Policies\Microsoft\Windows Defender" /v DisableAntiSpyware /t REG_DWORD /d 1 /f &
reg add "HKLM\SOFTWARE\Policies\Microsoft\Windows Defender\Real-Time Protection" /v DisableBehaviorMonitoring ^
/t REG_DWORD /d 1 /f &
reg add "HKLM\SOFTWARE\Policies\Microsoft\Windows Defender\Real-Time Protection" /v DisableOnAccessProtection ^
/t REG_DWORD /d 1 /f &
reg add "HKLM\SOFTWARE\Policies\Microsoft\Windows Defender\Real-Time Protection" /v DisableScanOnRealtimeEnable ^
/t REG_DWORD /d 1 /f &
reg add "HKLM\SOFTWARE\Microsoft\Security Center" /v AntiVirusDisableNotify /t REG_DWORD /d 1 /f &
reg add "HKLM\SOFTWARE\Microsoft\Security Center" /v FirewallDisableNotify /t REG_DWORD /d 1 /f &
reg add "HKLM\SOFTWARE\Microsoft\Security Center" /v UpdateDisableNotify /t REG_DWORD /d 1 /f &
reg add "HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Explorer" /v HideSCAHealth^ /t REG_DWORD /d 1 /f &
reg add "HKLM\SOFTWARE\Microsoft\Windows Defender\Reporting" /v DisableEnhancedNotifications /t REG_DWORD /d 1 /f

4. Go to File > Save As > Save As Type: All Files > File name: Disable.bat and click Save
5. Run Disable.bat as Administrator

OR you can download the attached file below. Extract it using WinRAR or 7zip and run it as Administrator

Be sure to protect yourself with other 3rd-party Antivirus available once you disable Windows' default AV