The cable bracket mechanism is extendable between a cleat or clamp mounted to a building and a part of a bay or bow window that is remote from the building. The mechanism includes an elongated bracket having a right angle flange at one end that extends away from its main body in a direction opposite the hook portion at the main body other end, a cable having one end connected to a building and at its opposite end to a stud extended through an aperture in the flange, a bracket having the hook portion connected thereto and being mounted to the window and fasteners threadable on the stud to bear against the flange for adjusting the tension in the cable.