Your Dell laptop's "Function" key, which is labeled "Fn" on the keyboard, gives you the option to change settings or toggle features by tapping a combination of keys. Its possible to accidentally lock the "Fn" key if, for example, you drop the laptop or your cat sits on your keyboard. To unlock the "Fn" key, you only need to press two keys simultaneously. Once the "Fn" key is unlocked, you can use it to modify settings such as the display brightness and speaker volume.
Press and hold the "Fn" key, which is located in the lower left corner of your keyboard, to the left of the "Ctrl" key and to the right of the "Windows" key. Holding the "Fn" key down, tap the "Num Lk" key at the upper right corner of the keyboard to unlock the "Fn" key.
Hold down the "Fn" key and tap the "F3" key to bring up the Dell battery monitor screen. Tap "Fn" and "F10" together to eject the disk drive.
Hold down the "Fn" key and tap the up arrow key to increase the screen's brightness, or press the down arrow key to decrease the screen's brightness. Repeatedly tapping one of the keys increases or decreases the brightness to its maximum or minimum.
Tap the "Page Up" key while the "Fn" key is depressed to manually raise the laptop's volume. Use the "Page Down" key to lower the volume.
Press "F2" along with the "Fn" key to turn on or off the laptop's wireless card. Press "F1" with the "Fn" key held down to put the laptop into hibernate mode, which saves power while you aren't actively using the computer.
Not all Dell models use the exact key combination to unlock the "Fn" key. If "Fn" and "Num Lk" don't work for you, press "Fn" and "Shift" or "Fn" and "Scr Lk."
If you have multiple displays connected to your computer, holding "Fn" and tapping "F8" switches between the displays.