Abstract: Disclosed herein are systems, apparatus, and methods for mounting structures, for example panels, to doors, windows, and other building openings. Aspects and embodiments of the present invention are directed to a system of brackets which may be removably mounted onto a door, window, or other building opening and to which may be attached a protective panel which substantially covers the window or other building structure. Such a system may be used, for example, to provide protection to doors, windows and other building openings against flying debris from hurricanes and to other severe storms.