INFORMATION PROCESSOR AND PROGRAM REWRITING METHOD

PROBLEM TO BE SOLVED: To provide an information processor capable of rewriting a program to start up a system even in case that download fails on the way. SOLUTION: This information processor 1 comprises a nonvolatile storage part 12 storing a boot program in a boot area 22; a volatile storage part 13 storing a boot program 36 to be newly written to the boot area 22 instead of the boot program 26; and a processing part 11 writing the boot program to be newly written to the boot area 22 to a unused area 24 of the nonvolatile storage part 12 and then writing the boot program 36 to be newly written to the boot area 22 of the nonvolatile storage part 12. Even if upload of the boot program to the boot area of the nonvolatile storage part fails due to OFF of power supply during updating or the like, the system can be started up by the boot program stored in other than the boot area of the nonvolatile storage part. COPYRIGHT: (C)2005,JPO&NCIPI