Windows 10/116 min readReviewed 2026-07-29

Function keys control volume or brightness instead of F1–F12

Switch the keyboard function row between media actions and standard F-keys using Fn Lock or supported firmware settings.

Quick diagnosis

If Fn+F5 sends F5 while F5 alone changes brightness, the keyboard’s action-key layer—not Windows key failure—is active.

1
Test the Fn modifier
Compare one function key alone and while holding Fn.
2
Use the documented Fn Lock
Consult the exact keyboard manual; many models use Fn+Esc, but shortcuts vary.
3
Check firmware settings
On supported laptops, inspect Action Keys Mode or Function Key Behavior in the manufacturer’s firmware/settings utility.
4
Retest after restart
Confirm whether the choice is stored by firmware or requires the vendor utility.

Change the active function layer using the exact model’s supported shortcut.

Choose standard F-keys or action keys as the primary layer when the manufacturer exposes that option.

Change only the documented function-key option in firmware; record its original value.

• Repeat the Fn Lock shortcut or restore the firmware option to its prior value.

• If neither layer sends an F-key event, update the exact-model hotkey driver or test the keyboard hardware.

Fn is commonly processed inside keyboard firmware and changes which scan code another key sends.

How to lock or unlock the Fn key
HP Support. Model-scoped Fn lock and Action Keys behavior.

Diagnose it in this order

Compare one function key alone and while holding Fn.

Consult the exact keyboard manual; many models use Fn+Esc, but shortcuts vary.

On supported laptops, inspect Action Keys Mode or Function Key Behavior in the manufacturer’s firmware/settings utility.

Confirm whether the choice is stored by firmware or requires the vendor utility.

Solutions

Change the active function layer using the exact model’s supported shortcut.

Choose standard F-keys or action keys as the primary layer when the manufacturer exposes that option.

Change only the documented function-key option in firmware; record its original value.