Good news for Windows 10 users:
You won't be able to turn off Cortana once the next obligatory update comes out.
Yes, Microsoft has decided for you, that Cortana is so awesome, that you should never ever just think on turning that stupid thing off.
I really hope that Steam OS takes over the games market, so I can finally get rid of Windows for good. That's anyway the last use case where I'm still stuck on Windows sometimes.
Oh by the way: Just as a random conspiracy theory because it fits so well here: Microsoft wants to make Steam buggy and broken, so Users switch to the (also buggy and even more broken) Windows Store.
I'm really looking forward to the release of ReactOS.
Stay in touch. Once it is official and I find a way to get rid of this feature I'll tell you how you can also do this [and here it is].
And as a short reminder: W4RH4WK wrote a set of Windows 10 Debloater PowerShell scripts.