Dell Inspiron 4100 - Manual (Page 67)

The PC Card slot has two connectors that support various types of PC Cards (also referred to as PCMCIA cards), including modems and network adapters.
Hard Drive
The hard drive reads and writes data on a hard disk.
Security Cable Slot
This slot allows you to attach a commercially available antitheft device to the computer. Instructions for installing antitheft devices are usually included with the
device.
Speakers
Press the volume control keyboard shortcuts to adjust the volume of the integrated speakers. If no sound comes from the speakers, press and adjust
the volume.
Right Side View
NOTICE: Before you buy an antitheft device, ensure that it will work with the security cable slot.
CAUTION: Do not block, push objects into, or allow dust to accumulate in the air vents. Doing so can damage the computer or cause a fire.
1 speaker (one of two) 5 network connector
2 infrared sensor 6 S-video TV-out connector
3 audio connectors 7 air vent
4 modem connector