Abstract: The present invention provides a method for providing an auxiliary basic input/output system (BIOS) code in a computer system, where the computer system includes a central processing unit (CPU) for executing an operation system (OS) program. The method comprises: providing a main BIOS memory for storing a main BIOS code to be executed in a main mode; providing an auxiliary BIOS memory for storing the auxiliary BIOS code to be executed in an auxiliary mode; and in the main mode, if a specific time interval expires and the OS program is not successfully executed, disabling the main BIOS code, enabling the auxiliary BIOS code, and resetting the computer system to switch from the main mode to the auxiliary mode.