For those like me that enjoy a "dual booting" PC, it's what one does when one retires (LOL) you might find the following article from "How-To Geek" interesting. (I'm sure login123 will)
"You probably shouldn’t install Windows 10 on your primary PC. But, if you are going to, you should at least install it in a dual-boot configuration. You can then reboot to switch between your installed versions of Windows."
http://www.howtogeek.com/197647/how-to-dual-boot-windows-10-with-windows-7-or-8/