Compaq EN Series Hardware Reference Manual page 25

11. Slide the expansion card into the expansion slot and press it
firmly into place.
Removing or Installing an Expansion Card
When you install an expansion card, make sure you press
firmly on the card so that the whole connector seats properly
in the expansion card slot.
12. Replace the screw at the side of the expansion slot.
13. Connect external cables to the installed card, if needed. Connect
internal cables to the system board, if needed.
14. Replace the computer access panel.
15. Reconfigure the computer, if necessary. Refer to Chapter 1,
"Installation Guidelines."
Hardware Reference Guide 2-17