An exemplary network system includes a remote computer and a network server. The remote computer includes a baseboard management controller (BMC), a south bridge chipset, a power button, and a switching circuit. The switching circuit has a control terminal connected to an output of the BMC, a power terminal connected to a power supply, and also connected to a SB_PWRBTN pin of the south bridge chipset, and a ground terminal connected to ground via the power button. The network server is connected to an input of the BMC of the remote computer, the network server outputs a control signal for forbidding activating the remote computer, the BMC receives the control signal and outputs a low level voltage signal to turn off the transistor, and the remote computer can not be activated.