Provided are a computer system and a method of booting the same. The computer system includes: a first storage unit for storing a booting-related program including an operating system program and data, the stored program and data being retained even when a power voltage is not supplied; and a second storage unit for storing data, the data being lost when the power voltage is not supplied for a predetermined time or longer. The method includes: a first step of performing a booting operation using the booting-related program stored in the first storage unit and storing the booting-related program stored in the first storage unit in the second storage unit when the second storage unit is detected and the booting-related program is not stored in the second storage unit; a second step for performing a booting operation by executing the booting-related program stored in the second storage unit when the second storage unit is detected and the booting-related program is stored in the second storage unit; and a third step of backing up the booting-related program stored in the second storage unit to the first storage unit when a predefined backup condition is met.