Electric device, start method of electric and update method of BIOS

This invention discloses one electron device, which comprises central processor, memory, switch unit, basic input and output system, wherein, the memory sets two BIOS program memory areas; the BIOS switch unit is to electrify the device and to trigger the electron device switch from one BIOS program memory area to other electron device; the switch unit is to electrify the device or to break the CPU to the division address wire and to conduct division wire for electron device start. This invention also discloses one start method and BIOS update method.