I did an automatic update a while back,and as with everything new,I was not the happiest little computer-illiterate elf on the planet!!! But I am completely used to it now and even prefer certain aspects of it!! I only do very basic things on my computer anyway,so it is not really a big deal to me at all!!
From what I have learnt Windows 10 is free to download and install and ofcourse it is the latest. But it will work only if your existing Windows is an 8 if not it will keep stalling. As mine is Windows 7 I have decided to leave it at that.
In my absence, my husband put it on our laptop. It is the pits if you are only semi-literate with computing. Fortunately he did not get to the desktop. Had I been around I would have advised him not to as I had not heard a good word about it. There are instructions for ridding your computer of it if it has not been installed for over two weeks. Google them..
I have Windows 8 and really don't like it as 7 was much better. I'd made my own short cuts which saved heaps of time but with 8 it's not as easy to do that and it annoys me when I can't do things quicker than from a menu. As with all Microsoft releases they never iron out the bugs before releasing the product so 10 is a definite no-no for me.