No concrete date has been given by Microsoft regarding the actual release of Windows 9.

Some sources report that the update will be available to users at around 2015. However, other reports claim that Windows 9 will be launched publicly by the fall of 2014.

Although no official reports have been released, Windows 9 is rumored to be called "Threshold".

According to RedmondMag.com, Windows 9 will be a free upgrade for users of other Windows platforms.

"Microsoft could be planning to entice users of older Windows editions by offering free upgrades to "Windows 9" next year," the report shared.

Tech blogger and Microsoft expert Paul Thurrott also shared this supposition.

"Threshold is more important than any specific updates. Windows 8 is tanking harder than Microsoft is comfortable discussing in public, and the latest release, Windows 8.1, which is a substantial and free upgrade with major improvements over the original release, is in use on less than 25 million PCs at the moment," Thurrott surmised.

This speculation was further strengthened by an article written by ZDNet Microsoft reporter Mary Jo Foley.

"Microsoft officials are still not talking publicly about Threshold/Windows 9. There are rumors Microsoft is planning to offer Windows XP, Windows Vista and Windows 7 users some kind of deal — possibly even a free upgrade to Windows 9 — in order to get them to move to the latest Windows version once it's out next year," Foley wrote.

In addition, the reporter hypothesized that the Windows update might be available in the spring of 2015.

"Microsoft's original plan was to make this update a much bigger and more important release. The Windows team originally was aiming to make the new "mini" Start Menu part of this second update, but scrapped that plan a couple of months ago, deciding instead to make the new Start Menu a feature of Windows "Threshold." Threshold, likely to be called Windows 9, is still sounding like a Spring 2015 deliverable," Foley continued.