Administering client computer (3) is connected to a plurality of facsimile machines (1) over a LAN (2). The facsimile machines (1) store quick-dial telephone numbers in RAM (11), and operating programs in flash memory (13). The computer (3) sends replacement data for the quick-dial telephone numbers and the operating programs of the facsimile machines (1) to the facsimile machines (1) over the LAN (2). The facsimile machines that receive the replacement data then overwrite the telephone numbers and operating programs with the replacement data.