I would have chosen the Windows 10 forum but to go back to your old Windows is widely discussed. Here's one of hundreds of sites about it.
http://www.howtogeek.com/220723/how-to-uninstall-windows-10-and-downgrade-to-windows-7-or-8.1/
I did not give any site mission to download windows 10 on my PC . As a matter of fact I did nine yet and I live alone no one else lives with me and when I went on a vacation when does 10 was downloaded on my computer . My Internet which and I pay for high speed is so slow like a turtle and the only number I can get to help me is from the Microsoft store where I literally had to hold on for two hours and eventually hung up . I want this off and I also keep getting the scam companies trying to sell me 500.00 virus walls and prevention. I work from home for a large company and I just bought my brand-new Dell PC and equipment less than a year ago and I am serious I need someone to please help me get this off Of my computer

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic