Super_Leprechaun

It really depends but my preference right now would be 8.1 because if you follow the way there os work is that they alternate from a good to a bad os to a good os every release so based on that windows 9 will be good and I don't know if Microsoft will support upgrading from windows 7 to 9 but they will most differently support 8 to 9

I have a 500gb ssd, 2 120 gb ssd's, a 1tb hdd and a 2tb hdd and i am currently running windows 8.1 on one of the 120 gb ssd's and want to put ubuntu and osx on the other 120gb and was wondering how i control what os has access to what hdd/ssd/partition?