A computer includes a motherboard with a signal receiving port and a switch circuit. The switch circuit includes a force sensing module and a transistor. The transistor includes a first terminal connected to the force sensing module, a second terminal connected to a power source, and a third terminal connected to the signal receiving port. When there is a pressure applied to the force sensing module, the force sensing module outputs a first driving signal to turn on the transistor and enables the computer to maintain its current power on or off state. When there is no pressure applied to the force sensing module, the force sensing module outputs a second driving signal to turn off the transistor and switches on or off the computer.