Computer system having expansion unit

Claim 1

A computer system comprising: a computer; and an expansion unit to which the computer is detachably attached in order to expand a function of the computer, wherein said expansion unit comprises a hard disk drive, said hard disk drive having an access lock function for inhibiting an access to said hard disk drive when an input password does not coincide with a predetermined password, and said computer comprises: resource detection means for detecting a resource housed in said expansion unit when attachment of the computer to the expansion unit is detected, the resource including said hard disk drive; determination means for determining whether or not said detected resource is a hard disk drive which is in an access inhibit state; memory means, coupled to the determination means, for storing an event indicating that the hard disk drive is in an access inhibit state, and for issuing the event indicating that the hard disk drive is in an access inhibit state; password input means for, through an operating system, displaying a guidance for prompting to input a password in response to issuance of the event indicating that the hard disk drive is in an access inhibit state from said memory means; means for attempting releasing the access inhibit state of the hard disk drive by making the hard disk drive which is in the access inhibit state valid and by supplying the password input from said password input means to the hard disk drive which is made valid; and resource assigning means for assigning the hard disk drive to the operating system when the access inhibit state of the hard disk drive is released.