A computer network system includes a plurality of information provider computers, an information collector computer and a communication network for connecting these computers together. The information provider computers store therein a plurality of information sets in connection with respective generation number information including ID codes and version codes. The information collector computer stores therein the information sets in connection with the version codes, periodically or intermittently receives the generation number information, compares the same against corresponding information stored therein, and receives the information set if a corresponding version code is not stored therein.