A power management system for a personal computer comprises a power management processor, a switchable power supply and a keep alive power supply. The processor is powered by the keep alive power supply that continuously provides power. The computer is powered by a power supply that is switchable in response to a control signal. The processor preferably controls the switchable power supply. The processor is coupled to receive external device interrupts from a plurality of external devices that instruct the processor when to turn the switchable power supply on and off. The processor is also coupled to the computer through an interface. The power management system also includes a method for turning the computer on and off. A preferred method uses the processor to control the power provided to the computer. The preferred method also uses the processor to dictate whether the computer will to perform a long boot that brings the computer to an operational state, identifies the computer's configuration, and tests memory, or a short boot that brings the computer to an operational state in a much shorter time. A preferred method for turning the computer off includes the ability to exit a program being run by the computer, and saving a hardware state of the computer on a hard disk.