The next version of Windows is slated to arrive by April 2015 as the current version, Windows 8, is "tanking", according to a report.

The new iteration, Windows 9, is codenamed "Threshold", according to a report from blogger Paul Thurrott.

"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," wrote Thurrott.

Thurrott claimed Microsoft will release more details about its Windows-related plans at its Build developer conference in April this year.

Those plans might include an update to Windows 8.1 as well as Windows Phone 8.1, both of which should ship in April 2014.

Microsoft will reportedly overhaul its Metro design language in Windows 9, and although it won't be released as an alpha version during the Build conference, the company plans to launch three milestone releases of Windows 9 before the final version hits shelves.

"It's not clear what changes are coming, but it's safe to assume that a windowed mode that works on the desktop is part of that," wrote Thurrott.

Sydney Morning Herald