Image processing apparatus, and function executed method and function executed program in the apparatus

An image processing apparatus includes: a user identification unit that identifies a user of the apparatus; a registration determination unit that determines whether the settings required for using a function of the apparatus are registered in a user registration unit when a user issues an instruction to execute the function, the settings being related to the user having issued the instruction, the user registration unit being capable of registering settings for each user with respect to setting items including items required for using the function and arbitrary items; a first execution unit that executes the function when the registration determination unit determines that the settings required for using the function are registered; and a second execution unit that performs a predetermined operation other than execution of the function when the registration determination unit determines that the settings required for using the function are not registered.