In some examples, a socket locking system can comprise a socket; a printed circuit board (PCB) card disposed in the socket; a first locking handle and a second locking handle to lock the PCB card in the socket; and a PCB retention band including: an elongated closed loop forming a first distal end and a second distal end opposite from the first distal end, wherein the first distal end is to contact the first locking handle and the second distal end is to contact the second locking handle; and a retention portion coupled to the elongated closed loop of material to contact a top surface of the PCB card to disposition the PCB card in the socket.