Gateway ALR 9250R User Manual page 25

Lift the CPU drawer to the same height as the mounting rails and align
2.
the rails on the drawer with the cabinet mounting rails.
Insert the side rails on the CPU drawer into the cabinet mounting rails
3.
and push the drawer evenly into the cabinet until the latches on the
drawer rails lock. See the illustration Installing the Drawer below.
Installing the Drawer
Chapter 1: Getting Started 11