You can also upgrade a PC by doing a fresh install of Windows 10, even if it doesn’t have any operating system installed. Your PC will get a genuine, activated Windows 10 key-just like it worked during Windows 10’s first year when the free upgrade offer was officially being advertised. Assuming you’re using a Windows PC with a genuine and activated Windows 7 (or Windows 8) key, you can upgrade to Windows 10 in just a few clicks.