A method to automatically convert a format of a file through an image forming apparatus, the method including displaying list of tasks executable by the image forming apparatus and a list of files stored in the image forming apparatus, selecting a task to be executed from the list of tasks and a file from one or more files stored in the image forming apparatus that is an object of the selected task, converting a format of data of the selected file into a bitmap format and converting the bitmap format of the data into a format that is compatible with the selected task, and executing the selected task using the converted file.