Powershell, spustený ako Správca!!!
Remove-Item -Path "C:\ProgramData\Microsoft\Windows Defender\Scans\History\Service\*" -Verbose
------------------------------------------------
v Núdzovom režime, cmd.exe:
del "C:\ProgramData\Microsoft\Windows Defender\Scans\History\Service\DetectionHistory\*"
del "C:\ProgramData\Microsoft\Windows Defender\Scans\mpenginedb.db"