To provide an automatic converting device driver for device type data for automatically changing the setting of device type data of a device having device type data, which can not be recognized by the operating system(OS) of a connected system, so as to recognize them through the OS of a system, which can not recognize these device type data, without changing the setting of data peculiar to an existent device itself.

Without changing the setting of data peculiar to the existent device itself, the device type data acquired from an ATAPI device 1 are compared with device type data, which can be recognized by an OS 4, and when both the device type data are not coincident, the device type data acquired from the ATAPI device 1 are converted to device type data which can be recognized by the OS 4.