HP EliteDesk 800 Hardware Reference Manual page 37

c. Connect the fan plug to the system board (3).
22. Align the hard drive guide screws with the slots on the hard drive cage, press the hard drive down into
the cage, then slide it forward (1) until it stops and locks in place.
23. Rotate the hard drive latch down (2) to engage the hard drive.
24. Replace the access panel.
For instructions, see
25. If the computer was on a stand, replace the stand.
26. Reconnect external devices, plug in the power cord, and then turn on the computer.
27. Lock any security devices that were disengaged when the access panel was removed.
Replacing the computer access panel on page 14.
Replacing the WLAN module 31