A driver (4, 5) of a window lift mechanism to simplify subsequent adjustment of a window pane. The driver (4, 5) includes a flat receiving fork (7) having first and second sides (9, 10). A screw (14) extends through the receiving fork (7) for pulling the first and second sides (9, 10) together. In the vicinity of the axis of the screw (14), the first side (9) includes a number of openings (19). A pressure piece (13), which can be operated from outside of the first side (9), protrudes through the openings (19) into a gap (8) between the first and second sides (9, 10). The pressure piece (13) can be displaced in a substantially parallel direction to the axis of the screw (14). A threaded nut (11) contacts the pressure piece (13) to operate the pressure piece (13).