Abstract: A bracket, for facilitating installation of window units, has a support arm and a lower arm, parallel to and spaced apart from each other, and interconnected by a transitional section. Two or more brackets may be used during installation of a window. The lower arm of each bracket is positioned under the sill member, so that the transitional section comes close to the interior edge of the sill member, and each support arm passes over, and cantilevers beyond, the sill member. The window being installed may then be temporarily supported on the cantilevering support arms. Retainers such as screwdrivers may be positioned in holes provided near the ends of the support arms to prevent the window from sliding off the support arms. The brackets may be nailed or screwed to the sill member through holes provided in the transitional sections.