An interface controller initializing method for an information processing device equipped with multiple interfaces of the same type comprises the steps of: detecting control of an interface executed by a first control unit; detecting an end of the control of the interface by the first control unit executed according to instructions regarding the control of the interfaces issued by a second control unit; detecting abnormality regarding the control of an interface by the first control unit; allowing a user to input an initialization instruction for initialization of the first control unit; and executing the initialization of the first control unit on condition that the abnormality regarding the control of an interface by the first control unit has been detected, the initialization instruction has been inputted, and the end of the control of at least one of the other interfaces by the first control unit has been detected.