A control device includes: a random number generating unit that generates a random number; a first setting unit that sets the random number in a first storage; a message creating unit that encrypts the random number using a public key of the administrative server and to create a request message to be transmitted to the administrative server; a timer starting unit that starts a timer; an activation unit that activates the system software; a timer canceling unit that accepts an interruption from the system software and cancels the timer; a message verifying unit that verifies the notification message from the administrative server using the public key and the random number; and a restart unit that restarts the system software while limiting the functions, in the case where the timer expires time or the verification fails.