WinApi::deleteFile

[AlexeyS]

попробуйте не WinApi, а NET

    boolean         ret = true;
    FolderPath   pathFrom, pathTo;
    FileName        fullFileName;
    System.Exception clrException;
    ;

    pathFrom = this.getImportPath();

    fullFileName = pathFrom + "\\" + _fileName;

    if (!System.IO.File::Exists(fullFileName))
    {
        warning("Не найден файл " + fullFileName);
        return false;
    }

    pathTo = this.getImportPathLocal();

    if (System.IO.File::Exists(pathTo + _fileName))
    {
        System.IO.File::Delete(pathTo + _fileName);
    }

    try
    {
        System.IO.File::Move(fullFileName, pathTo + _fileName);
    }
    catch (Exception::CLRError)
    {
        ret = false;

        clrException = CLRInterop::getLastException();

        if (clrException)
        {
            clrException = clrException.get_InnerException();
            if (clrException)
            {
               error(clrException.get_Message());
            }
        }
    }