After the old Windows 10 installed you would be presented with Microsoft suggesting you use a Microsoft account to login with rather than a Local user account to Windows 10. However you would have the option to choose a local account if you preferred.
With the latest version of Windows 10, this option has now gone, and Microsoft are forcing you to create a Microsoft account to go any further with the Windows 10 Setup.
For admins, this is a nightmare so my suggestion would be to get hold of an older Windows 10 install disk / USB, and during the install when it asks to connect to the internet, DONT.