A new update to Microsoft's Windows Operating system, Windows 8.1 is available to download for free.
Unveiled at the annual Build conference Windows 8.1, it brings a host of new functions and features, here are the 10 best.
Perhaps the most controversial change from Windows 7 to Window 8 was the removal of the start button.
Microsoft has listened to users and instead of a series of tiles, the Start button is back at the bottom left hand corner of the screen.
2: Live Tiles
The Live Tiles on the Start screen are now resizable with small and large sizes available. The tiles can also display more information.
For the first time, you can use personalised photos as wallpaper on the Start screen. In addition the Lock screen can pull in photos from SkyDrive or the photos folder.
The Windows 8.1 search facility has been enhanced - it now searches the web, including Microsoft apps like Xbox Music, as well as documents and SkyDrive.
Searching for an artist or place can produce results from a range of different media at once - termed Search Heroes. This can include video, music and web links.
SkyDrive is Microsoft’s cloud service and Windows 8.1 brings deeper integration than ever.
Apps update automatically in the background - even if they've been updated on a different device.
6: Split screen
In Windows 8, you could view two apps in a split screen view. In Windows 8.1 this has been enhanced. Multiple apps can be displayed on the screen at the same time and they can be resized so they take up as much or as little space as you like, and can even be moved around.
Now up to four apps can be displayed at once, up to a miniumum resolution of 500 dpi, so if there aren't enough pixels on the screen you may be limited to two simultaneously.
7: XBox Music
Microsoft’s music app has been updated with a new layout, making it easier than ever to listen to music - in fact, you can listen to a tune within two clicks.
There’s a new music discovery feature similar to Pandora, find a song you like and you can listen to radio stations with similar tunes.
8: Windows Store
The Windows Store has been updated so finding apps is easier than ever, with new apps, popular apps and personalised recommendations.
Interestingly, Microsoft has removed the five device limit on the number of devices an app can be stored on and app updates are automatic too.
9: Booting to desktop
The ability to boot to desktop means users can bypass the Start screen and go straight to the desktop mode, which looks and feels more like Windows 7.
10: And to finish
Reading List lets you peruse web pages offline. The camera has a panorama mode and the Internet Explorer browser supports unlimited tabs.