Hi,
I know that the Fn keypress cannot be handled through the higher level windows apis because it needs to be in combination with another key before the keypress is registered.

But.... I was wondering if there was something I could do at a lower level using assembly.
Any ideas would be welcome.
Thanks

I thought the Fn key went straight to the SMM code or is held by the KBD controller while waiting. If that is so then there is most probably nothing you can do in any CPU code (asm or other) to capture it.

damn ok, what about EFI I've never had much to do with EFI, but is there nothing that can be developed and loaded somehow pre-boot? sorry a bit vague need to read up on these technologies.

Some Fn keystroke sequences never get to the non-system code. For example: my brightness keys (Fn+Up and Fn+Down) will work no matter what OS is running, even a crashed OS won't stop me from changing the brightness. The keystrokes go directly to the SMM code. To get access you would need to know how your chipset works internally and then set-up all the various control registers for SMM control.

@keyoke: I do not understand your question: Fn keys are all coming into your window procedure with focus. Just use WM_KEYDOWN message. Or, are you asking about a different thing?

AsmGuru62: Laptops have a "Fn" key for accessing extra functions.

I see... there is a key Fn which ALTERS the meaning for F1-F12.
I thought that Fn meant Functional keys, like F1-F12.

The Fn key alters the meaning of many other keys in addition to the F1-F12 keys.

One observation - Windows probably can detect these keys. For example when I press Fn+F2 (WiFi on/off) Windows shows the information picture that displays "WiFi enabled" message.

Yes, when you press the second key in combination with Fn it is registered into Windows through the system board driver. I think the OP wanted to detect just the Fn keypress without a combination key.