Free of charge? That depends just on the label they will stick on it.
A Windows 8 Service Pack 1 will be free, but they will charge you for a Windows 9 (or some other funny name the marketing department will come up with).
I installed Windows 8 over my trusty Windows 7 installation again and then upgraded to Windows 8.1 for all of 5 hours before I formatted the SSD and installed Windows 7 again. What a crock of poo.
It seems clear to me now that Micro$oft have absolutely no interest in desktop PCs anymore and expect them to become extinct.
Planning is an unnatural process, much better to just get on with things, that way failure comes as a complete surprise instead of being preceeded by a period of worry and doubt