A disclosed unauthorized usage prevention system enables execution of at least one software item including an identification information item uniquely associated with the software item, based on a key information item in a key module. An information processing apparatus includes a key information storage unit, a control unit, an unauthorized usage prevention controller, and a port. The unauthorized usage prevention controller includes a connection recognition unit and a key information copying unit. When the unauthorized usage prevention controller recognizes that the key module is connected to the port, the unauthorized usage prevention controller copies the key information item in the key module into the key information storage unit, and the control unit enables execution of all of the software items with identification information items associated with the key information items held in the key information storage unit.