The number of people who must have installed Win10 by accident is huge.
It is so easy for the install to be started, particularly if you are not very techie and do the 'click windows to get rid of them' thing.
I know lots of people who would click away then ask what did I do.
(Usually that is point I am asked to help ....... some people never seem to learn 'if not sure do nothing!'. )
There are lots of small PC shops making a tidy profit out of fixing broken/hung/partially working PC's & Laptops after win10 has been 'let loose'.
Very nice of MS to support the small businesses in the PC Arena.
As kitz has found out there has been a recent run on bits & pieces that people need to try to recover their machines. (Cables / Caddies / Disks / Ball Pein Hammers etc etc )
[OK ... maybe not the Hammers, although if you cannot fix the problem they can make you briefly feel better with some moderate exertion & financial cost..
]