Earlier we heard the rumor about Microsoft offering Windows 9 (aka Windows Threshold) to Windows 8 users free of cost. Now another rumor is brewing about Windows 9, the successor of Windows 8.1. Rumor is, Microsoft may go as far as offering Windows 9 free upgrade to Windows XP, Vista and Windows 7 users? Expected to land in spring 2015, Windows 9 is now one of the most anticipated Windows next edition. Microsoft is also expected to offer a minor update, dubbed Update 2 to all Windows 8.1 Update 1 users.