Abstract: An installation tool adapted for driving leader hooks into the side of a building for supporting a leader of a gutter system is disclosed. Conventionally, leader hooks are driven by means of a projecting shoulder using a hammer or other such compressive tool. The difficulty in installing these leader hooks has arisen as a result of the shoulder being relatively narrow and difficult to engage with blows of a compression tool. To this end, the installation tool is in the nature of a cap adapted to receive the head and shoulder of leader hooks having rectangular or circular-shaped heads. The installation tool, by being adapted to accommodate either shape, avoids the necessity of having to maintain a separate tool for each shape leader hook.