The present invention relates to an information apparatus and method suitable for use in upgrading control programs readily by a user. In step S501, a storage area to store an upgraded firmware is determined. In step S502, the upgraded firmware is provided. In step 503, the provided firmware is decrypted and re-encrypted. In step S504, re-encrypted firmware is written into the storage area determined in step S501. In step S505, a maximum marker is detected. In step S506, a value obtained by adding 1 to the maximum marker provides the marker corresponding to the storage area in which the firmware was stored in step S504. The present invention is applicable to, for example, an audio data server.