Because Windows 10 uses PowerShell for its configure, you can use it to install Windows Server 2016 without using the Desktop edition. To do so, you must have the latest x64 release of Windows 10 installed. That’s not always possible, but once you have the latest version, you can activate the full Windows Server 2016 install in x64 bit mode.
PS>From a more technical point of view, what happens is that the bootloader on x64 Windows 10 will be the Universal Bootloader and only boot the latest x64 Windows version available. A x86 Windows installation will use the Microsoft Bootloader and will boot the latest x86 Windows OS. In your case, that is x64 Windows. Installing the 64bit bootloader is the bootloader that will handle activation.
Note: for more complex reasons without interest for this article, if you use Windows 10 Enterprise it will be installed as a 32bit version pre-installed in a x64 machine. If you want to create a x64 build of Windows just use Windows 10 Pro or Upgrade.
Windows Server 2016 evaluation x64 : you can activate this version of Windows Server 2016 using the Windows Server 2016 installer. When asked to sign in, you can choose to use a local account or a local and domain account. You then must use the correct activation key on the evaluation version of Windows Server 2016 (the actual key used to install it). When you do this, the evaluation version is activated and can be upgraded to a full version of Windows Server 2016. d2c66b5586