The following short batch script will automatically remove “Scan with Windows Defender” from the context menu for files, folders and drives in Windows 10.

:: Removes Windows Defender from the Context Menu for Files
REG DELETE HKEY_CLASSES_ROOT\*\shellex\ContextMenuHandlers\EPP /F
:: Removes Windows Defender from the Context Menu for Folders
REG DELETE HKEY_CLASSES_ROOT\Directory\shellex\ContextMenuHandlers\EPP /F
:: Removes Windows Defender from the Context Menu for Drives
REG DELETE HKEY_CLASSES_ROOT\Drive\shellex\ContextMenuHandlers\EPP /F