Apparatus for preventing unwanted access to a disk drive is disclosed. A housing has a surface adapted to overlie the slot, an internal piston chamber extending inwardly from one end of the housing, and a lock receiving chamber intersecting the piston chamber immediate the ends of the housing. A fixed latch member extends outwardly from one end of the housing, and is provided with a lip at its distal end. A movable latch member is attached to a piston located in the piston chamber and projects outwardly parallel to the fixed latch member. The movable latch member has a lip at its distal end extending outwardly so that the lips of the respective latch member extend away from one another. The piston is movable inwardly with respect to the housing so that the latch members can be inserted into the disk drive slot, and thereafter the piston moves outwardly so that the lips of the latch members engage the corners of the slot. A lock mechanism is located in the lock receiving chamber of the housing. The lock mechanism has a hasp movable from an unlocking position and a locking position which locks the latch members in engagement with the slot.