HP Compaq 320 Notebook-PC - Manual (Page 111)

12. Tighten the bottom door screws. (3).
NOTE: Refer to the illustration that most closely matches your computer.
13. Replace the battery.
14. Turn the computer right-side up, and then reconnect external power and external devices.
15. Turn on the computer.
Upgrading a memory module in the primary memory module slot 99