I found the solution to this problem at:
http://answers.yahoo.com/question/index?qid=20121227004715AAu7ZM7
The solution provided by 'shakira':
go to start menu
search up "brightness"
click on adjust screen brightness
On the side you will see "Panel Open-Power On" click on that
go to keyboard tab
check the option that says "Standard F1~F12 mode"
then it'll say that you have to restart computer click yes to restart now or restart later
When ur computer is done restarting u wont have that problem
This works.
Actually NO, it doesn't work, at least not here. There is some sort of confusion mode Airplane Mode has, that screws things up and refuses to let it turn off. I went the whole route, trying every bit of information and advice for it, and nothing worked.
I finally had to do a Win 10 full return to out of box configuration and right now it's working. Howe ver, I've had it working before and after a reboot it just comes back. It's doing an update at the moment, so when I finish with that, if the problem stays
gone, I'll come back and confirm it; probably not until this evening.
BTW, using a Reinstall USB stick doesn't fix the problem either; At least here in a DELL XPS 8700. For the time being, all is fine.
Later, gator