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Key highlights

• The Fn key enables dual functionality for the F1 to F12 keys, allowing access to both standard and secondary commands.
• The quickest method to lock the Fn key is through your keyboard, though this feature isn't available on all devices.
• Another option is enabling Fn lock via the Windows Mobility Center.

Understanding how to use the function (F) keys on your keyboard can significantly boost efficiency. Utilizing Fn lock options enhances this experience, as each F-key can execute two different actions—ranging from multimedia controls to system-specific shortcuts.

By combining the Fn key with any of the F1-F12 keys, you can switch their behavior instantly. This guide will also show you how to unlock or lock the Fn key for more convenient use in Windows 10 or Windows 11.

Table of contents

• How the Fn key interacts with function keys
  • Standard vs. Alternate functions
• Methods to lock and unlock the Fn key
  • Keyboard shortcuts
  • Windows Mobility Center
  • BIOS settings

How the Fn key interacts with function keys

This section explains the role of Fn lock. The Fn key works similarly to Shift or CapsLock. If you frequently type documents, you're familiar with their behavior: holding Shift capitalizes individual letters, while pressing CapsLock enables continuous uppercase typing without holding a key.

Similarly, the Fn key modifies the behavior of F1 through F12. It toggles between standard and alternate functions.

Standard vs. Alternate functions

Using a function key without Fn activates its standard function—such as adjusting screen brightness, controlling volume, muting sound, toggling Wi-Fi or Bluetooth, or playing/pausing media. Pressing Fn in combination with these keys triggers their alternate (typically legacy) functions like F1, F2, etc. You can release Fn at any time to revert to standard operations.

Locking the Fn key in Windows 10 or 11 reverses this behavior: the F-keys will default to their alternate (F1-F12) functions until unlocked. While locked, pressing Fn temporarily restores the standard multimedia functions—similar to using Shift to type a lowercase letter while CapsLock is active.

Methods to lock and unlock the Fn key

Below are various ways to manage Fn lock, which may differ based on your device brand and model. Since function key layouts vary across manufacturers, not all keyboards support the same Fn locking methods.

This guide covers several approaches:

Keyboard

The most straightforward way to lock Fn is directly through your keyboard, though this depends on hardware support.

Some keyboards feature an F Lock key. Pressing it toggles between standard and alternate modes. Keyboards with this feature often include an LED indicator to show the current state.

If your keyboard lacks an F Lock, look for FnLock, sometimes represented by a padlock icon with "Fn" labeled on it. This key is commonly shared with Esc, Shift, or CapsLock. To enable Fn lock, press and hold the Fn key, then press the FnLock key. To disable, repeat the same key combination.

Windows Mobility Center

To open Mobility Center, press Win X or right-click the Start button to access the Quick Access Menu in Windows 10 or 11. From the list, select "Mobility Center." This opens a window with several system controls. Locate the "Function Key Row" option, which includes a dropdown menu offering two choices: “Function key” or “Multimedia key.” Selecting “Function key” enables Fn lock, while “Multimedia key” restores default behavior.

You can access Mobility Center anytime to toggle this setting. However, not all laptops include this option—even if the Mobility Center opens, the Function Key Row setting may be missing depending on your hardware.

BIOS

BIOS (or UEFI on modern systems) allows deep-level hardware configuration, including Fn key behavior. To enter BIOS, click Start, click the power icon, and hold Shift while selecting Restart. When the blue options screen appears, navigate to Troubleshooting > Advanced Options > UEFI Firmware Settings, then click Restart. Your PC will reboot into BIOS.

Inside BIOS, mouse control isn't available, but keyboard arrow keys allow navigation. Go to the Main tab, find the "Function key behavior" option, and select it. Choose "Function key" to enable Fn lock. Once done, press F10 to save changes, then confirm with Yes when prompted.

Now you know how to lock or unlock the Fn key with ease. Not too complicated, right?

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