An apparatus including a main chassis and a system component chassis removably mounted in the main chassis through an opening in a top portion thereof. A positioning member is attached to the system component chassis. A handle is pivotally attached adjacent to an end wall of the main chassis for being moved between a first position and a second position. The handle includes a portion engaged by the positioning member to position the system component chassis in a docking position with respect to the main chassis when the system component chassis is mounted in the main chassis with the handle in the first position. An insertion member is attached to the handle for engaging a portion of the power supply chassis for movement thereof from the docking position to a docked position when the handle is moved from the first position to the second position. System components such as a power supply may be quickly and reliably mounted in and removed from a low profile chassis of a computer using a vertical drop-in, horizontal movement mounting technique.