[adorno]

...but need to make it free for every Microsoft User like Apple and Amazon do and not just the 16 million Windows 8 users

First off, OSX is not free, and Apple's prices for every device are so high that, the OS can be included with the devices. Microsoft does not make the devices from which it can charge a higher price which would include the OS, other than the Surface tablets. For devices smaller than 9 inches, the OS from Microsoft is already free (aka: included, a la Apple). Apple's OS is really a component of the entire device, and none of Apple's OSes are sold separately, like the Windows OS.

Secondly, the number of MS users on Windows 8 is way over 200 million, and likely closer to 300 million by now; not the 16 million you quote.

[Enlightened1]

According to this article from PC WORLD. There are more Vista users than Windows 8! It’s 16 million for Windows 8. Please read the quote below from PC WORLD.

“At the end of 2013, there were almost 715 million copies of Windows installed in businesses worldwide, and more than half—361.2 million—were Windows 7, according to IDC. About 224 million were Windows XP, and almost 40 million were Windows Vista. Little over 16 million were Windows 8.”

http://www.pcworld.com/article/2688752/with-new-os-microsoft-will-try-to-put-windows-8-era-behind-it.html

[Enlightened1]

iOS and OS X are both free now.

“Just like 10.9 Mavericks and the other Apple operating systems, the public is expecting to get the new OS X Yosemite upgrade for free for compatible Apple devices.”

http://www.christiantoday.com/article/os.x.yosemite.update.oct.21.release.date.coincide.new.apple.ipads/41012.htm