To improve downloading efficiency over the Internet, while managing bandwidth during downloading operation, for downloading a large file, such as an executable file.

Plural data segments, including a part of the file to be downloaded, are encapsulated in a set of image files. Reference to the set of image files is included in a web page definition. The image file, which the segments of the file to be downloaded are encapsulated, in is downloaded to the cache of a browser during drawing operation of the web page relevant to the web page definition. The segment data taken out from the image file is assembled and the file to be downloaded are reproduced. When the target file is an executable file, installation operation is performed.