This is real! Some people have already succeeded.
It is possible to avoid the so-called microsoft tax/windows tax!

Here are some links:
WindowsRefund.info :: Get your refund (english)
Linux.com | How to get a Windows tax refund(english)
Détaxe.org - Accueil du site(french)

I also fell on a world map of where people managed to get windows refunds, but I can't find it anymore.