The Delphi function below determines if defragmentation is needed for the disk on the local or remote computer. The function returns boolean indicator of whether or not defragmentation is recommended. This example utilizes TWmiQuery, TWmiMethod and TWmiConnection components. The source code below creates and destroys the components on the fly, so this function may be used in console- or UI-type applications.

// This function determines if defragmentation is needed for the
// disk on the target computer.
// When used for local host, the only required parameter is 
// Volume, for example "c:" 
//
// For remote computer, parameters must be: 
// TargetHost: name or IP address of the host, like '10.8.36.54' 
// UserName: name of the user, may include domain, like 'MOON\Administrator'; 
// Password: the user's password. 
// Volume: the volume to check for defragmentation need, for example "c:" 
function IsDefragmentNeeded(TargetHost, UserName, Password, Volume: string): boolean;
var
  vConnection: TWmiConnection;
  vQuery: TWmiQuery;
  vMethod: TWmiMethod;
  vSQL: string;
  vResult: integer;
begin
  Result := false;
  vConnection := TWmiConnection.Create(nil);
  vQuery      := TWmiQuery.Create(nil);
  vMethod      := TWmiMethod.Create(nil);
  vQuery.Connection := vConnection;
  vMethod.WmiObjectSource := vQuery;
  try
    vConnection.MachineName := TargetHost;
    vConnection.Credentials.UserName := UserName;
    vConnection.Credentials.Password := Password;

    // try to connect. It may fail if the destination computer does not have
    // WMI (like windows 95, 98, NT without WMI core installed), or
    // if the provided credentials are not valid
    try
      vConnection.Connected := true;
    except
      Exit;
    end;

    vSQL := 'select * from Win32_Volume where name = "' + volume + '\\"';
    vQuery.WQL.Add(vSQL);
    vQuery.Open;
    if not vQuery.EOF then
    begin
      vMethod.WmiMethodName := 'DefragAnalysis';
      vResult := vMethod.Execute;
      if vResult = 0 then
        Result := vMethod.OutParams.ParamByName('DefragRecommended').AsBoolean
        else writeln(vMethod.LastWmiErrorDescription);
    end else
    begin
      writeln('Could not find volume ' + volume);
    end;

  finally
    vMethod.Free;
    vQuery.Free;
    vConnection.Free;
  end;

end;