Patent ID: 7840794

Claim:
An OS (Operating System) starting method of an OS that is stored in a hard disk of an information processing apparatus, the OS starting method comprising: starting a BIOS (Basic Input Output System) stored in a storage section when it is determined that a power is turned on; searching for a boot device that can be started; starting a boot OS being found and stored in an external storage medium; displaying a password input screen on a display section; generating an unlock password for the hard disk to be started by concatenating information unique to the external storage medium with an input password inputted by an input section and converting a concatenated result to a hash value; determining whether a setting of security of the hard disk to be started is performed; unlocking a locked state of the hard disk with the unlock password when it is determined that the setting of security of the hard disk to be started is performed; starting a MBR (Master Boot Record) of the hard disk whose locked state is unlocked; starting a boot loader of the OS; starting the OS; and performing the setting of security of the hard disk when it is determined that the setting of security of the hard disk is not performed.