Updating and restoration method of system file

摘要

PCT No. PCT/JP95/00300 Sec. 371 Date Jan. 18, 1996 Sec. 102(e) Date Jan. 18, 1996 PCT Filed Feb. 27, 1995 PCT Pub. No. WO95/27941 PCT Pub. Date Oct. 19, 1995Operating Systems (OS's) of the same form are stored in first and second memory areas. The executing Operating System in the first memory area is terminated and the Operating System in the second area is initiated. After system files stored in the first area are released from access lock, they are replaced by substitute files provided in advance by using a file replacing function of the second Operating system. When such a file replacement fails for some reason, the original operating system files are immediately restored by using a backup file. By this invention, the updating of files previously forbidden by the Operating System in the first memory area to be accessed as well as the restoration of files at the time of update failure can be achieved by software.