Abstract: A door for a computer case is provided which can be moved to a blocking position for blocking access to bays and/or drives of the case. The door can be attached to the case by a slide connection for sliding it along the front of the case between its blocking and accessing positions. In the preferred form, the case is a vertical tower type of case and the door is preloaded on track guides so that when it is raised such as to the blocking position it will not fall back to the accessing position under the influence of its own weight. A gear drive can be provided between the door and housing to provide for smooth manual sliding of the door to readily allow the door to be pushed to overcome the frictional resistance provided by the preload without hang ups in the track guides.