function keys preset to help, screen brightness, etc. Don't function in programs

Aaaargh. Is there any way to change these keys so that I can use them for their intended purpose when I am working in programs like Excel? I don't even appear to be using the right term as my Win Explorer comes up blank . . . is there a fix that doesn't take a geek to understand? Cuz I'm not! ;-]

Thanks, Clare

OK, well I see no one could answer my question, but I found the answer in somebody else's question: use the "fn" key. I feel kinda like a l-user now, but at least I'm satisfied (there's the joke: who are you gonna satisfy with that? and the guy says, "me" ... use ur imagination for part one of the joke).