This isn’t much of a post, but I suspect some people will find it useful =).

If your laptop is acting as if your function key is always held down; e.g. the F1-F12 keys do the special action (change volume, or whatever) instead of their normal purpose, then try Hold Fn + Esc and, depending on your model, it may disable the “Function Key Lock”.

On my laptop this actually shows a picture of a lock with the letters Fn within it to indicate it locks the function key as on.  But I didn’t see that in advance and had to google more than I would have liked to figure it out.