Look guys - if you are at all worried that Microsoft could install it on your computer without you knowing, and don't tell me that's not possible, here is a little program that will stop that happening and still allow you to install Windows 10 down the track.
It's all free and the site makes good reading for what has and might happen.
It's called GWX Control Panel. Just google it and you'll be right.
I've had it on my computer for about six months now and no probs.