Windows 10 release slated for autumn 2015 - Microsoft COO Kevin Turner

Hurried replacement for Windows 8 out in time for next Christmas, promises Microsoft COO

Microsoft Windows 10 will be released in the autumn of 2015, according to Microsoft chief operating officer Kevin Turner.

While the operating system is expected to be completed by the summer, it is unlikely to appear on PCs and laptop computers before late September, missing the "back to school" surge in PC sales.

Turner promised that the operating system would be a "complete reboot", including an intelligent personal assistant that anticipates what users are doing in order to speed up its operation. It follows the release of a "technical preview" in October, which will be followed up by further information in January.

Turner indicated that Windows 10 would be more like Windows 7, which has proved enduringly popular. "The things people love about Windows 7, we will have available for them in Windows 10," he told Japan's Nikkei Asian Review.

Joe Belfiore, who is leading the development of Windows 10 as corporate vice president of PC, tablet and phone for Microsoft, has described the development as a "house renovation project".

Windows 10 will be launched almost three years to the day after the launch of the ill-fated Windows 8 operating system, which was widely panned when it was released on 26 October 2012. Microsoft tried to pitch Windows 8 as an operating system that could run both touch-screen devices, including tablet computers, as well as conventional PCs.

Instead of winning over users, it effectively put people off, contributing to the prolonged downturn in desktop and laptop PC sales. Reports suggest that the company rejected user feedback that indicated that the Windows 8 "Metro" user interface would prove unpopular.

However, Microsoft is persisting with that dual use paradigm. The Metro interface - renamed Modern - said Belfiore, was "an effort to try to address a bunch of those problems, like you see on mobile devices - an app can only write to its own storage, it has to get authorisation to do things like use GPS or your location, it has an updating mechanism that's built-in".

Windows 8 also heralded an unusual split in operating systems, with a different and incompatible "RT" version for ARM-based devices, particularly tablet computers, as well as Windows Phone 8, which ran solely on smartphones.

Microsoft has since made Windows 8 free for low-cost tablet computers, but is still struggling to be price-competitive against devices that run Google's Android operating system, which now start at just £50.