Provided is a system including a computer, a display device for performing display based on a signal from the computer, and an access point for performing communication between a wired network and a wireless network and disposed between the computer and the display device. In response to operation for turning ON the display device or to a power ON instruction from another client device, the access point is activated and sends an activation signal for activating the computer. Upon receiving the activation signal, the computer is activated and outputs a signal to the display device. Further, in response to operation for turning OFF the display device or to a power OFF instruction from another client device, the access point sends a power shutoff signal to the computer and shuts off its own power. Upon detecting the power shutoff signal, the computer performs a shutdown process. When the signal from the computer stops being received, the display device shuts off its own power.