The newest version of Microsoft's flagship operating system announced on Thursday will be a successor to today's Windows 10, which the company introduced in 2015.

In a challenge to rival Apple, the company also announced that it won't force app developers to pay fees to Microsoft for using its app store; and that Google's popular Android apps will run on its new system.

Windows 11 is expected to become available later this year on new computers and other devices and as a free update for those with Windows 10.

It includes a host of cosmetic upgrades, a revamped task bar and sounds and under-the-hood features designed to boost speed and efficiency.

The Start button and menu have been moved to the centre, away from its traditional left position.

Microsoft's virtual announcement event was affected by technical difficulties, forcing the company to recommend some viewers watch it on Twitter instead.

When it launched Windows 10 six years ago, Microsoft was hoping that the new operating system would help it rebuild loyalty among users who were increasingly relying on tablets, smartphones and other devices.

Windows has been a PC workhorse for decades.

Its first version launched in 1985, offering computer novices a "graphical user interface" so they could click on icons and menus with a mouse button rather than simply type commands into a blank screen.

It has been a core part of Microsoft's business ever since, although its influence waned as PC sales declined with the rise of smartphones.

Microsoft said it would allow developers to bypass the payments system in its app store if they have their own commerce engine.

with PA

Australian Associated Press