Indicator Lights | PC Users Bible

Most laptops have a row of status indicator lights directly under the monitor screen. In many computers, these are backlit symbols that light when the associated function is active. On some computers, a second, more limited set of indicators is visible from the top of the case, near the hinge.

Unfortunately, every manufacturer uses a somewhat different set of symbols, so it's not always obvious what each light means. The most common indicator lights include:

Power On: The Power On indicator lights when the computer is turned on. It blinks when the computer is in standby or hibernation.
AC Power Status: The AC Status indicator lights when the computer is connected to an external power supply.
Battery Status: The Battery indicator lights when the battery has an adequate charge, and blinks when the battery needs a recharge.
Disk Activity: The Disk Activity indicator lights when the internal disk drive is reading or writing data.
Wireless Activity: The Wireless Activity indicator lights when the wireless network interface is active.
Bluetooth Status: The Bluetooth indicator lights when the Bluetooth interface is active.
Network Activity: On some computers, an LED indicator next to the Ethernet port flashes when the computer is sending or receiving data.
Caps Lock: The Caps Lock indicator lights when the Caps Lock key is active.
Scroll Lock: The Scroll Lock indicator lights when the Scroll Lock key is active.
Num Lock: The Num Lock indicator lights when the Num Lock option is turned on and the computer uses the alternative 10-key numeric keys on the right side of the keyboard.

Your computer might not have all of these lights, and it might include one or more others. Your best sources of information about the lights on your own computer are the manual and the online Help screens.