Abstract: A BIOS updating system enables a computer to perform a BIOS updating process on original BIOS data. The BIOS updating system includes: an operational module that stores updating information including BIOS updating data in a memory device when the computer runs in an operating system executing stage, sets update booting parameters, and re-boots the computer; and an updating module that executes a pre-processing process, before the execution of the BIOS updating process, when the re-booted computer runs in a POST stage, including: an inspecting unit that inspects whether the update booting parameters are set and generates update commands; and an executing unit that acquires from the memory device the BIOS updating data via the updating information according to the update commands, so as to replace the original BIOS data with the BIOS updating data, and further reboot or shut off the computer after the updating of the BIOS data.