I do not know people, but Windowz 8.1 is out yesterday and it is free for Windowz 8 owners, just instaled it today on my mother MacBook Air.
Just go to the Microsoft Store and download it.
P.s. The only thing i hated was that after instaletion i had no way to log in to my computer with out using Microsoft public account, so i used it and after login to system i changed back to login by local password only.
Because with the resent Snowden discoveries and all other discoveries,that right now the US goverment is a bunch of criminals who can do what ever they want with out looking first in to US Constitution, so it is not safe to keep ur information on public services,until we have goverment which follows US Constitution.