function TWMIPhysicalDriveListGetter.IsHarddrive(const MediaType: String):
  Boolean;
begin
  //Refer https://msdn.microsoft.com/en-us/library/aa394132%28v=vs.85%29.aspx
  result := Pos('hard', LowerCase(MediaType)) >= 0;
end;

function TWMIPhysicalDriveListGetter.IsDriveConnectedByKnownInterface: Boolean;
begin
  result :=
    IsDriveConnectedBy('IDE') or
    IsDriveConnectedBy('SCSI') or
    IsDriveConnectedBy('USB');
end;

procedure TWMIPhysicalDriveListGetter.IfDriveConnectedByKnownInterfaceAddToList;
begin
  if IsDriveConnectedByKnownInterface then
     AddDriveToDeviceIDList;
end;

procedure TWMIPhysicalDriveListGetter.CheckMediaTypeAndAddIfRequirementMet;
begin
  if IsHarddrive(CurrentDrive.MediaType) then
    IfDriveConnectedByKnownInterfaceAddToList;
end;