The Fn or Function keys are located at the top of a Windows 10 laptop. They have two distinct functions: media control and app control in general. When tapping one of these keys, users must hold down the Fn key to switch between these activities.

The Fn keys on Windows 10 toggles between the primary and secondary states/functions of the Function keys. This key functions similarly to the Shift key in that it must be kept down in order to use the Function keys’ secondary functions. It is not a switch that can be turned on or off.

How to toggle Fn keys on Windows 10

Toggle Fn keys on Windows 10

On a Windows 10 laptop, you may simply change the primary function of the Function keys, but you must do so using BIOS. However, you’ll have to settle for a Fn key that toggles the functionality if you want to modify the primary function of these keys from within Windows 10.

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Hardware limitations

The Fn key can be ‘locked,’ that is, it can be turned on, causing the Function keys to perform their secondary functions. The Function keys revert to their primary function when the Fn key is switched off.

All of this can be done from Windows 10, and you don’t need to boot into BIOS, although it does depend on the keyboard you have. A key on your keyboard that can lock the Fn key must be present (see Escape key in screenshot below).

How to toggle Fn keys on Windows 10

Toggle Function keys

To enable the Fn key lock, follow these steps.

  1. Tap the F1 key on your keyboard and see what it does to determine the primary function of the key.
  2. Tap and hold the Fn key on your keyboard.
  3. While holding the Fn key, tap the Fn lock key and then release both keys.
  4. Tap the F1 key and it will execute its secondary function.
  5. To unlock the Function keys, hold down the Fn key.
  6. While holding down the Fn key, tap the Fn lock key once and release both keys.
  7. The function keys will revert back to their primary function.

How to toggle Fn keys on Windows 10

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Function keys are often handy in games, however they cannot be utilized within the game if their primary action is set to control media, brightness, WiFi, and other system settings rather than allowing the game (or any other app) authority over them. There aren’t many programs that can toggle the Fn keys or apply a virtual “Fn lock” on the fly. You’re out of luck if your keyboard doesn’t have a Fn lock key.