disable windows updates.
This should be done as soon as windows has been installed on a computer anyway.
But it's amazing how many people let microsoft stick any old crap on their machine because some monkey at the shop told them to.

Using a neat little piece of free software called Classic Shell: http://www.classicshell.net/
You can make wndows 8 look and behave almost exactly like windows 7. It's one of the most things I do these days.
Uless you plan on getting a windows phone & tablet alongside your desktop or laptop and buying a bunch of crappy microsoft apps - there is NO POINT in installing windows 10.

Stick with 7 or classic shelled 8.