Windows 10 64-bit Cannot Download iTunes 12.8 - Solved
With the latest (for me at this time) iTunes, Apple appears to have discontinued the ability to download the iTunes64Setup.exe utility, if your machine is Windows 10 64-bit (x64). It now appears to be restricted to the Microsoft Store App iTunes.
Unfortunately for me, my developer machine has been unable to get iTunes to update itself with a new version of iTunes for quite some time now (at least, since 12.0). I have to do a complete uninstall, then reinstall of iTunes, to get the new version going.
My attempts to get the iTunes App from Microsoft Store to work, have proved to be unsuccessful, to wit: the App will install and recognize my music, but is unable to install the appropriate iPhone driver. It attempts to do so with a message "the driver required for this iphone is not installed" and begins downloading something that it cannot install, despite many unsuccessful attempt to do so. This includes reboots and "Run As Administrator".
However, lucky me, I discovered on my own, how to fool the Apple website to download the latest iTunes64Setup.exe (probably used by Windows 7 SP1 x64 users), by using the hacked-together URL: https://www.apple.com/itunes/download/win64/. I hope Apple does not close this loophole, or if it does then restore the ability of Windows 10 machines to get the EXE and skip Microsoft Store altogether. For those in a similar situation, I hope this URL helps you out too.
iPhone 6, Windows 10