Microsoft officially ended the free Windows 10 upgrade offer for Windows 7 and Windows 8.1 users in July 2016. However, the upgrade mechanism itself remains functional. Installing Windows 10 on a machine that previously had a genuine Windows 7, Windows 8, or Windows 8.1 license often results in automatic activation. The activation servers recognize the hardware and grant a digital license for Windows 10.
Once you have installed an authentic Windows 10 Pro ISO, you can use the operating system indefinitely. An unactivated version of Windows 10 functions completely normally, with only a few minor restrictions: Windows 10 Professional Preactivated X64 Original Iso
Are you trying to upgrade an or building a brand-new system ? Microsoft officially ended the free Windows 10 upgrade