A public preview of Windows 8.1 was made available June 26.

At the time, Microsoft said it had sold more than 100 million licenses for Windows 8 but that the update was planned after listening to customers.

Some analysts say Microsoft was forced to act because of slow adoption of Windows 8, which made some radical changes to the design of the desktop.

With Windows 8, Microsoft was trying to create a system that could be used on mobile touch screen devices while also serving the users of traditional PCs.

Microsoft launched Windows 8 last October, revamping its flagship system in an effort to make inroads in the fast-growing mobile segment. At the same time, it launched its Surface tablet computer.

Copyright Agence France-Presse, 2013