PURPOSE: To eliminate the re-system generation(SG) or to stop it to the necessary minimum at the time of installing an operating system.

CONSTITUTION: An SG information object segment name input means 12 inputs an SG information object segment name 11, an SG information object segment name address converting means 13 converts the SG information object segment name 11 to an address, and an SG information object segment table registering means 14 stores the address in an SG information object segment list table. An OS part saving means 22 saves an OS part 211 of an operating system 21 stored statically in a shipment object 23, and an OS part loading means 24 loads an OS part 251 to a new SYS.SYSTEM 25 from the shipment object 23. An SG information part saving means 29 saves an SG information part 202 in an intermediate medium 27 from an old SYS.SYSTEM 20, and an SG information part loading means 26 loads an SG information part 252 to the new SYS.SYSTEM from the intermediate medium 27.