Windows 10: How to use function keys without the fn key?

I have purchased an external keyboard since the keyboard on my laptop has failed. I don't have the fn key on my external keyboard. So how can I use the function keys. I tried pressing them but no functions come. For example F2 is to lower the brightness but when I press F2 on external keyboard nothing happens. Also I have enabled the Action Keys in the BIOS menu of my HP laptop. So please help.

:)

 

FN key always on

If you press “Num Lock" (might also be labeled "Num Lk”) (I’ve also seen it labeled “Pad Lock” for numeric Pad) it turns on the blue keys, and inverts the meaning of the “Fn” key – it’s a way to use that embedded numeric keypad without having to hold down the “Fn” key the entire time. To fix it, just find and press the “Num Lock” or “Pad Lock” key again. (Note, sometimes these keys are themselves “Fn” keys, so you may, or may not, need to also hold down the “Fn” key to get the right function.) Often there is an indicator light associated with the setting.

 

FN key always on

To clarify, I was saying "Accessibility" features maybe be controlled via the BIOS, not the Fn keys. And one of the Accessibility features makes the keys "sticky". This allows folks with some disabilities to press, for example, the Ctrl key, then the Alt key, and then Del in sequence instead of all at once. Same with the Fn key. The sticky feature would let you first press the Fn key, and then the F9 key (for example) and not Fn + F9 at the same time to enable/disable whatever Fn + F9 does with that notebook (it is the touchpad on my Toshiba).

 

FN key always on

Are you sure it is not a mechanical issue with the key's switch?

Check also the notebook's "Accessibility" features. These make the Fn key a "sticky" key so folks with disabilities don't have to press the Fn key and another key simultaneously. This may be in the BIOS but it may also be in notebook's own software that loads at boot. And the OS itself will have some "accessibility" functions. On my Toshiba, the default is for the "Sticky Fn" key to automatically unstick after a couple seconds but there is an option in the menu to disable the automatic unstick feature - meaning it stays "pressed" indefinitely.

Last, if this notebook's OS has been updated, you might check the notebook's webpage for driver updates.