What’s new in Windows 8.1?

Microsoft has officially released Windows 8.1 – an update to its Windows 8 operating system – during a keynote speech at its annual developers conference in San Francisco.

The free test version of the update is available to download now and the full version will be released to Windows 8 users later this year.

The lock screen is being turned into a “cloud-powered photo frame” that will shows photos stored on the device and in SkyDrive.

Windows 8.1 also includes a vastly improved “search” function, which allows a user to search for documents, apps, or items on the Internet from a single search bar.

It also allows users to see all their applications immediately in a grid by swiping down or pressing a button on-screen.

There are new personalization options for tiles including colors and fonts.

Users can also customize the start screen much more easily; changing sizes of app icons or controlling which apps appear.

For the first time, it will be possible to open two windows simultaneously in the new-look interface.

Windows 8.1 includes Microsoft’s latest browser, Internet Explorer 11, and lets the user restore the address bar and tabs to the screen view.