1. An image processing apparatus comprising: an operation unit that is to be operated by a user; a communication interface; an image processing engine; a memory storing a plurality of software; a display; and a controller configured to: in response to receiving a first start instruction for executing image processing based on a user's operation of the operation unit, execute association processing associated with the image processing by executing first software of the plurality of software; control the image processing engine to execute the image processing; execute load processing of loading predetermined data included in the first software by executing second software of the plurality of software, the predetermined data being for executing the association processing, the second software being different from the first software; in response to receiving a second start instruction of the image processing from an external apparatus via the communication interface, execute the association processing using the loaded predetermined data by executing the second software; and control the image processing engine to execute the image processing, wherein the controller is further configured to: in response to receiving a first association instruction associated with the image processing based on a user's operation of the operation unit, execute first display processing of displaying a first image associated with the image processing on the display by executing the first software; and in response to receiving the first start instruction based on a user's operation of the operation unit at a state where the first image is displayed on the display, execute second display processing of displaying a second image associated with the image processing on the display by executing the first software, the second display processing being included in the association processing, wherein in response to receiving the second start instruction from the external apparatus, the controller is configured to execute the second display processing by executing the second software without executing the first display processing, wherein the first software comprises first display software and engine control software, wherein the controller is configured to execute the first display processing and the association processing by executing the first display software, wherein the association processing comprises: the second display processing; and first activation processing of activating the engine control software, wherein the controller is further configured to, in response to the engine control software being activated, execute supply processing of supplying an execution instruction for controlling the image processing engine to execute the image processing by executing the engine control software, and wherein the predetermined data comprises first display software data and does not comprise engine control software data.