HP DC7800 - Manual (Page 175)

Computer Access Panel
To access internal components, you must remove the access panel:
1. Prepare the computer for disassembly ( Preparation for Disassembly on page 159 ).
2. Loosen the thumbscrew on the rear of the computer (1), slide the access panel toward the front of
the computer, and then lift it off (2).
To replace the computer access panel, reverse the removal procedures.
Computer Access Panel 163