Abstract: A system administrator of a wireless LAN 100 manipulates a personal computer PC1 to change a WEP key. The personal computer PC1 authenticates a memory card MC as genuine under management of the system administrator. In the case of the authenticated memory card MC, changed setting information, as well as a previous WEP key before the change of the setting information, is written into the memory card MC. The system administrator then inserts this memory card MC into a memory card slot of a printer PRT1. The printer PRT1 authenticates the memory card MC as genuine under management of the system administrator. In the case of the authenticated memory card MC, the setting information is updated. This arrangement effectively relieves the user's workload in setting wireless communication devices, while ensuring the sufficiently high security.

Abstract: In a network control system that enables interconnected operation between multiple devices connected to a network, the user selects two devices as desired objects of interconnected operation, among a TV receiver 100, a projector 200, and a printer 500. The user directs and manipulates an infrared remote control 300 toward each of the selected devices to specify the device as an object device of interconnected operation. Each device receives an infrared signal sent from the infrared remote control 300 and executes control to allow for interconnected operation between specified devices. This arrangement of the invention enables the user to intuitively specify desired devices as objects of interconnected operation without using any special operation window.

Abstract: A system administrator of a wireless LAN 100 manipulates a personal computer PC1 to change a WEP key. The personal computer PC1 authenticates a memory card MC as genuine under management of the system administrator. In the case of the authenticated memory card MC, changed setting information, as well as a previous WEP key before the change of the setting information, is written into the memory card MC. The system administrator then inserts this memory card MC into a memory card slot of a printer PRT1. The printer PRT1 authenticates the memory card MC as genuine under management of the system administrator. In the case of the authenticated memory card MC, the setting information is updated. This arrangement effectively relieves the user's workload in setting wireless communication devices, while ensuring the sufficiently high security.