HP dx6120 Hardware Reference Manual page 30

Hardware Upgrades
2–20
4. Before installing an expansion card, remove the expansion slot
cover or the existing expansion card.
a. If you are installing an expansion card in a vacant socket,
remove the appropriate expansion slot cover on the back of
the chassis. Pull the slot cover straight up from the socket
then away from the inside of the chassis.
Removing an Expansion Slot Cover
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