An adapter is configured to be installed on an existing cable, extending along a connector of the cable to present a latching surface on a flexible arm of the adapter for engagement with a latching surface within a latching member adjacent a port connector of a device. When these latching surfaces are engaged with one another, the cable connector is held in engagement with the port connector. The flexible arm may then be manually depressed to release the engagement of these latching surfaces. The adapter is installed on the existing cable by placing the cord of the cable between a pair of hooks extending in opposite directions from the adapter, and by then turning the adapter on the cord so that the hooks are brought into position to extend partly around the cord.