HP Compaq Presario CQ35-337TX Notebook PC - Manual (Page 18)

Bottom components
Component Description
(1) Battery release latch Releases the battery from the battery bay.
(2) Battery bay Holds the battery.
(3) Wireless module compartment Holds a wireless LAN module.
NOTE: To prevent an unresponsive system, replace the wireless
module only with a wireless module authorized for use in the
computer by the governmental agency that regulates wireless
devices in your country or region. If you replace the module and
then receive a warning message, remove the module to restore
computer functionality, and then contact technical support through
Help and Support.
(4) Vents (5) Enable airflow to cool internal components.
NOTE: The computer fan starts up automatically to cool internal
components and prevent overheating. It is normal for the internal
fan to cycle on and off during routine operation.
(5) Hard drive bay Holds the hard drive and the memory module slots.
8 Chapter 1 Notebook tour