I have a key labelled Fn in blue letters at the bottom of my Windows 7 keyboard. I want to trigger my AutoHotkey script whenever someone presses that key.
The problem with the Fn key is, that a lot of keyboards don't implement it as normal key, but as a modifier that changes the key messages of other keys pressed at the same time.
So here is an example scenario of how Windows could see your input:
Press F1 down - Windows receives the F1 down code
Press F1 up - Windows receives the F1 up code
Press Fn down - Windows doesn't get anything
Press F1 down - Windows receives the media ▶ down code
Press F1 up - Windows receives the media ▶ up code
Press Fn up - Windows doesn't get anything