Dell Latitude D420 - Manual (Page 19)

Media Base Setup Guide 17
Installing the Optical Drive
1 Save and close any open files or programs, and turn off the computer.
2 Insert the optical drive into the bay on the media base. (See "Right View" on page 8.)
3 Insert the securing screw that holds the optical drive in place.
4 Turn on the computer.
The operating system recognizes the new drive.