Abstract: A cooling device for cooling a heat-generating component in a computer consists of a heat sink and a heat pipe having a portion fitted into a hole of the heat sink to be totally enclosed thereby. The heat sink consists of a number of mounting plates and heat dissipating fins alternately stacked together. Each mounting plate has two pegs on a top face thereof and two depressions in a bottom face thereof, wherein the pegs extend through a neighboring heat dissipating fin to fit into the depressions in a neighboring mounting plate, whereby the length of the heat sink can be easily adjusted by adding or reducing the number of the mounting plates and the heat dissipating fins. Thermally conductive adhesive is used between the heat sink and the heat pipe to fixedly connect them together.