A power adapter is provided for a computer including a power port and a housing defining an aperture. The power adapter includes a power head, a lock head disposed on the power head and a main housing including a body affixed to a security element, wiring for supplying power to the computer extending through the body to the power head and a lock system selectively actuatable with a key to orient the lock head in first and second orientations. The first orientation is characterized in that the power head is movable relative to the aperture for power head insertion into and removal from the power port. The second orientation is characterized in that the power head is immovable relative to the aperture.