My laptop has Windows 7 installed which I am perfectly happy with! I've heard from some people that installing Windows 10 can cause problems with your computer. I left my laptop on the other day but closed the lid as I intended to go back on it shortly afterwards. When I went back to it an hour later and opened the lid, Windows 10 had downloaded onto my laptop! I did not request, click for it or want it. I wonder is it even legal for them to do this without your permission?? I googled this and managed to revert back to Windows 7. I've heard from other people that Windows 10 has downloaded onto their computers also when they have left them switched on but not in use. If this happens to you and like me you do not want Windows 10, go into google where you will find the solution to revert back to your original setting. The cheek of them!!