An SSID and an encryption key of a wireless LAN apparatus of computer peripheral equipment are calculated based on a manufacturer's serial number of the computer peripheral equipment to be stored in the wireless LAN apparatus of the computer peripheral equipment. On the other hand, for an SSID and an encryption key of a computer wirelessly connected to the computer peripheral equipment, when driver software of the computer peripheral equipment is installed, a user inputs the manufacturer's serial number of the computer peripheral equipment, and the SSID and the encryption key of a wireless LAN apparatus are calculated on the computer to be stored in the wireless LAN apparatus of the computer. Thus, the same SSID and encryption key as those of the computer peripheral equipment can be set in the computer.