Method for decoding encoded and inaccessible Hitachi hard disk

The invention discloses a method for decoding an encoded and inaccessible Hitachi hard disk and belongs to the technical field of information security. The method comprises the following steps of: 001, enabling the hard disk to enter a factory mode; 002, decoding the encoded hard disk; and 003, switching the factory mode to a user mode. The method has the beneficial effects that firstly, firmware of the hard disk is read, so that the internal work of the hard disk is controlled and the reading and writing of an internal parameter module of the hard disk and the calling of a program module of the hard disk are realized; and secondly, an NVRAM (nonvolatile random access memory) chip is accessed in a security mode by utilizing the hard disk and a firmware zone start mark is modified, so that information in a C group password module is read and written in an A or B group password module and the purpose of decoding is achieved.