A computer housing includes a disc storage device mounted detachably on a top surface of a housing body. The disc storage device includes a casing formed with a receiving recess for receiving an optical disc, a cover body connected pivotally to the casing and operable so as to move from a closed position to an open position, a biasing member disposed between the casing and the cover body for biasing the cover body to move from the closed position to the open position, and a releasable retaining member disposed on the casing and the cover body for retaining the cover body at the closed position. An engaging unit is disposed on a lower side of the casing of the disc storage device and the top surface of the housing body for detachable engagement between the housing body and the casing of the disc storage device.