How to use the Fn key lock on Windows 10

The easiest way to lock the function keys is with the Fn lock key. Just press the Fn key and the Fn lock key simultaneously. When you let go of the keys, the Fn key will be locked, making it a little easier to use their secondary functions.

What are the function keys, anyway? Keyboards have a row of many keys at the top, above the number keys, that are labeled F1 to F12. These keys are present on practically all keyboards, regardless if they’re for Macs or PCs. These are dual use keys, so they perform two different functions, such as control volume, brightness, or music playback.

Fn Lock Key Feature

The simplest way to understand this feature is that it lets you access function key operations without having to press the Fn key.

On a PC, the default action of the Fn keys is set in the BIOS. Your keyboard has a Fn key that, when held down, will allow you to use the alternate command keys of the function keys.

Some laptops let you lock the Fn keys. This is like how the caps lock key works, which allows you to type all capital letters. The Fn key lock works the same way: when you turn it on, it’s like you’re holding down the Fn key.

For example, if one of your Fn keys on the function key row section controls media by default, turning on the Fn key lock will let you press that key by itself and manage media playback, without using the Fn key. It works the same way for the other function keys, too.

Not all keyboards have a Fn key lock. This is purely subject to the keyboard maker and is not something to do with drivers or a Windows 10 feature.

Tip: You can remap the function keys to make them work better for your needs.

3 Methods to Lock and Unlock the Fn Key

The keyboard method is the least complex method to lock and unlock the Fn key, but there are two other methods that let you change the function key behavior if that one doesn’t work for your particular keyboard.

Keyboard Method

We recommend this method for most people because it just requires pressing Fn with another key to lock or unlock all the secondary function keys.

1. Press the Fn key, and keep it held down.

2. While still holding the Fn key, press the Esc key once. Note that your keyboard might not work this way — look for a key with the lock symbol on it; that’s the one you want to press here.

   

3. Let go of both keys to instantly lock Fn keys.

To undo unlock Fn lock, simply repeat these steps.

Windows Mobility Center Method

If you have a laptop, you can also use the Windows Mobility Center to enable Fn lock.

1. Search for Windows Mobility Center from the Windows 10 Start menu. Or, enter mblctr in the Run dialog box.
2. Find the area of this program called Fn Key Behavior, and select the menu in that section.
3. Choose Function key to enable the Fn key lock. To unlock the key so that it behaves normally, choose Multimedia key.

   

You can lock and unlock the Fn key this way. Just swap the menu item in that lest step to return the Fn key to its normal behavior.

BIOS Method

The BIOS setup menu is another way you can lock the Fn key. This is the most advanced method of the three covered in this article, but it’s still very doable if you follow the steps correctly.

1. On Windows 10, go to Settings > Update & Security > Recovery.
2. Select the restart option to reboot your PC.
3. On the Advanced Startup Options menu, go to Troubleshoot > Advanced options.
4. Choose UEFI Firmware Settings > Restart.
5. Now that you’ve accessed BIOS, open Advanced from the menu, and look for Function Key Behavior in the list of options (use the up or down arrow key to navigate). Select it by pressing Enter.
6. Select Function Key from the pop-up menu.

   

7. Press F10 to save and exit BIOS (if that doesn’t work, check the menu at the bottom of BIOS to see what the save/exit Fn key is for your computer).

You can see that the BIOS settings look similar to the Windows Mobility Center settings. Therefore, to disable Fn lock, simply return to Step 6 and select the other option.