A door module for installation in a motor vehicle door is provided. The door module comprising a door module carrier to be installed in a motor vehicle door and a plurality of functional components of a motor vehicle door pre-installed on the door module carrier that are to be installed together with the door module carrier in the motor vehicle door. There is at least one guide rail of a motor vehicle window lifter amongst the functional components pre-installed on the door module carrier that can be fixed in an operating position at fastening points on the door module carrier side such that it extends in the operating position along the adjustment direction of the window pane to be adjusted by means of the window lifter. To this end there are at least two different sets of fastening points on the door module carrier side, spaced apart from each other, on the door module carrier that serve to selectively arrange the one guide rail of the window lifter in a first or at least one other different operating position, wherein the guide rail is aligned in each operating position to guide the window pane that is to be adjusted by means of the window lifter along the adjustment direction thereof.