Function Keys Not Working? How to Toggle Fn Lock So F1-F12 and Media Keys Behave

Pressing F1–F12 controls volume, brightness, or media instead of acting as function keys — or the function keys work but the media controls don’t.

Why: The top row of most laptops and many keyboards is dual-purpose. A single setting, Fn Lock, decides whether a tap on that row sends the standard F1–F12 keys or the special media/system actions printed on them. Nothing is broken; the lock is just set the way you don’t want.

Fix 1: Hold the Fn key to get the other action right now

This is the quick, no-commitment way to get the key you need.

1. To use the other behavior for a single press, hold the Fn key and then press the F-row key.
2. For example, if F5 is set to refresh but currently lowers brightness, hold Fn + F5 to refresh. If it’s the reverse, hold Fn and press the key to trigger the media action.
3. If holding Fn gives you what you want, you just need to flip the lock permanently — see Fix 2.

Fix 2: Toggle Fn Lock permanently

Fn Lock switches which behavior is the default so you don’t have to hold Fn every time.

1. Look for an Fn Lock key. It’s often the Esc key with a small lock icon, or printed on the Fn key itself.
2. Hold Fn and press that key once. On many keyboards a small light on the Fn key turns on when the function keys are locked into F1–F12 mode, and off when the top row acts as media keys.
3. Press the F-row again to confirm the behavior switched. Toggle once more if you locked it the wrong way.

If your keyboard has no Fn Lock key, the same option usually lives in your PC maker’s keyboard/hotkey app or in the BIOS/UEFI (often called “Function key behavior” or “Action keys”).

Fix 3: Set it in the manufacturer or BIOS settings

Some laptops only expose this as a firmware setting.

1. Restart the PC and enter BIOS/UEFI (usually by tapping F2, F10, Del, or Esc during startup — your boot screen shows which).
2. Look under Configuration, Advanced, or System Configuration for Function Key Behavior, Action Keys Mode, or Hotkey Mode.
3. Switch it between “function key” and “multimedia/action key” as you prefer, save, and exit.

FAQ

What does the light on the Fn key mean? On many keyboards the light is on when the top row is locked to standard F1–F12 function keys, and off when those keys act as media/system controls. Press the F-row to confirm which way it’s set.

My keyboard has no Fn key at all. Full desktop keyboards may instead have an F Lock key. Press it to switch the top row between standard function keys and the alternate actions; an F Lock light shows the current state.

The change didn’t stick after restart. Then the lock is being reset by firmware — set it in the BIOS/UEFI (Fix 3) so it persists.

Sources: Microsoft Support — Use the special keys on Surface Keyboard, Microsoft Support — Special keys and function keys for Surface Keyboards or Type Covers