Image upload/manipulation error?

Code:
if(!empty($_FILES)){

                $num_files = count($_FILES);

                $config['upload_path'] = 'S:/xampp/htdocs/asdasdasd';

                $config['allowed_types'] = 'jpg';

                $config['max_width'] = '800';

                $config['max_height'] = '600';

                $this->load->library('upload', $config);

                for($i = 1; $i <= $num_files; $i++){

                    $field_name = 'file_' . $i;

                    $this->upload->do_upload($field_name);

                    $upload_data = $this->upload->data();

                    $new_file = $upload_data['file_path'] . $product_id . '_' . $i . '.jpg';

                    rename($upload_data['full_path'], $new_file);

                    

                    $config1['image_library'] = 'GD';

                    $config1['source_image'] = $new_file;

                    $config1['create_thumb'] = TRUE;

                    $config1['maintain_ratio'] = FALSE;

                    $config1['width'] = '80';

                    $config1['height'] = '60';

                    $config1['wm_type'] = 'overlay';

                    $config1['wm_vrt_alignment'] = 'bottom';

                    $config1['wm_hor_alignment'] = 'right';

                    $config1['wm_overlay_path'] = 'S:/xampp/htdocs/asdasdasd/w.png';



                    $this->load->library('image_lib', $config1);



                    $this->image_lib->resize();

                    $this->image_lib->watermark();

                }

                

            }