BEagle -
To open Device Manager in Win8:
Thank you, your hypothesis regarding saving battery power makes sense !
In fact I'd tried this after reading previous advice from Biggles 78, and before writing my last, but I'd tried to do it via the Apps. page, not the Tiles page, and was told that no App. matched my request, which is why I had eventually gone to the Control Panel, and not found Device Manager there either, just a Networking command to always Connect when in Range.
Have now unticked the save power option as suggested - which was selected, unknown to me !
I'm reluctant to try it - It Ain't Broke, So Won't Fix It - at the moment, but will bear this in mine when I next have to resort to battery power.
Muchas Gracias to both of you.
ExS.