To identify failure in connection devices connected to an information processor at an early stage.

The information processor includes: acquisition means for, upon starting a BIOS, recognizing each of the connection devices connected to the own processor and acquiring device information for identifying the connection device from each of the recognized devices; collation means for collating device information on a regular device predetermined to be connected to the own processor with the device information on the connection devices acquired by the acquisition means; and notification means for notifying of the connection device corresponding to the device information determined inconsistent with the regular device information by the collation means, as an unknown device.