To provide a hard disk driver by which blocks are divided so as to correspond to the number of blocks and a capacity ratio desired by a user when initially starting an information processor and when recovering the information processor.

In the hard disk driver Hd, an operating system and programs are recorded on a first block. A second block is used for recording data of the user. A program controlling the information processor 11 to convert, at a specified capacity ratio, the first block and the second block into first regions with the specified number of regions is recorded on a third block. In addition, by providing a fourth block recording a recovery program, system recovery can be performed.