Microsoft is to release a Windows 9 "technology preview" in late September or early October in a move intended to win back users disgruntled by the idiosyncrasies of Windows 8.
The technology preview will be available for download, although testers will be obliged to also take monthly updates that will be automatically installed.
It is unclear how Windows 9 will differ from Windows 8, although it is expected to include a proper "Start" menu, which Windows 8 had abolished, and the Cortana voice recognition assistant. It will also improve the operating system's usability for PCs using more traditional input devices, such as mice and keyboards, compared to Windows 8 touchscreen-centric user interface.
Microsoft went through several technology preview versions of Windows 8 before it was released - but largely ignored feedback. While advance versions of Windows 8 were only available to developers, the Windows 9 preview version will be available to anyone who wants to download it.
The release of Windows 9 was revealed by All about Microsoft's Mary Jo Foley, a long-time Microsoft watcher and journalist with ZDNet.
Foley believes that the much-derided "charms" toolbar will be expunged in Windows 9, while Metro applications will be able to be run on the desktop and Windows 9 will also offer virtual desktops for the first time.