To provide a technique whereby a user can carry out operations in the same operating environment, regardless of whether the user uses a computer inside a network system, or uses a terminal outside the network system. A network system comprises: a first computer used by a designated user; and a plurality of second computers capable of being shared by a plurality of users. A management device, if a storage device is utilized by the first computer, allows the first computer to connect to a designated storage area and execute the boot-up program stored therein. The management device, if the storage device is utilized by an external terminal used by the designated user, allows one designated computer selected from the plurality of second computers to connect to the designated storage area and execute the boot-up program, and allows the external terminal to connect to the designated computer.