Uninstall Windows 10 and Downgrade to Windows 7/8 - No Software Needed
Uninstall Windows 10 and Downgrade to Windows 7 or Windows 8/8.1. Basically, the version you had before upgrading to Windows 10.
UPDATE: This must be done with an administrator account.
This method only works if Windows 10 was acquired through upgrading Windows 7 or Windows 8. Also there is a limited time window to downgrade (to keep system files) so it is important to perform this downgrade as soon as possible.
Also, if you need to find the product key your Windows 10 computer is activated with, please see this video: https://www.youtube.com/watch?v=XZiESt0rFac
This tutorial will apply for computers, laptops, desktops, and tablets running the Windows 10 operating system (Home, Professional, Enterprise, Education) from all supported hardware manufactures, like Dell, HP, Acer, Asus, Toshiba, Lenovo, and Samsung).