Abstract: The present invention relates to a fastening means (1) for mounting doors or windows, which comprises frames (2) intended to be mounted in a mounting direction (26) in an opening (3) in a wall, a floor, a ceiling, said fastening means (1) comprises a bracket (5) intended to be mounted on the backside (8) of the frame (2) and at least one screw or bolt (9), intended to be screwed into the end portion (4) of the opening (3), said bracket (5) comprises at least one locking slot (6), said screw or bolt (9) comprises at least one locking projection (11) intended to be pushed into said locking groove (6) for fastening the frame (2). Said locking slot (6) consists of a groove (12) for example an U-formed groove, extending mainly in the longitudinal direction (22) of the frame (2), said locking projection (11) comprises the head (10) of the screw or bolt (9) or a head (10), which is covered by a casing (14) e.g.