Abstract: A digital computer system has a lock hold-down assembly for security. The assembly is secured at a standard expansion card slot in the computer unit, and includes a bracket mounted inside the unit, accessible through the slot. In the preferred embodiment, the bracket has an integral flange with an aperture therethrough and a plurality of tabs. A cover member has a plurality of hooks for engaging the plurality of tabs through the slot. The cover member also has a cable enclosure through which the power cable and peripheral cables may be run. The cover member further has an integral flange with an aperture therethrough. A lock is placed through both apertures, thereby securing the unit and cables to the lock. The lock is anchored as desired.