Abstract: A method controls a computing device with an security device wherein a first identification information is stored in said computing device and a second identification information is stored in said security device. The computing device has a BIOS program and an operation system program. The method includes the steps of executing said BIOS program of said computer system; fetching said first identification information and said second identification information; comparing said first identification information with said second identification information; and executing said operation system program if said second identification information matches said first identification information.