Information processing system operable with a detachable recording medium

An information processing system can have a portability of personal operation environment set information or the like to use an information processing apparatus and can also protect a copyright. A control command is transmitted from a CPU 11 to a system bus 18. An RAM 12, a non-volatile memory 13, a display 2, and an input/output control apparatus 15 are connected to the system bus 18. The system bus 18 and an I/O bus 19 are connected to the I/O control apparatus 15 and a signal of a control line is bidirectionally supplied to the I/O control apparatus 15. The I/O control apparatus 15, a keyboard 3, a mouse 4, an optical disc drive apparatus 5, and optional apparatuses 21 are connected to the I/O bus 19. The optional apparatuses 21 are constructed by a fixed magnetic recording apparatus 21a, a floppy disk drive 21b, a tape device 21c, and the like.