A computer startup method, a startup apparatus, a state transition method, and a state transition apparatus are described. When the computer is in a suspend-to-RAM (STR) state, the power consumption is a first power consumption. When the computer transitions from the suspend-to-disk (STD) state to the startup state, the time consumption is a first time consumption. The state transition method includes, when the computer is in the startup state, obtaining a first power state transition command to instruct the computer to transition from the startup state to a specific state; and to respond to the first power state transition command, making the computer to be in the specific state.