Windows 8.1 brings you the Windows Store, Start screen and Microsoft account, but also enhancements in personalisation, search, Store apps and cloud connectivity – and the security and reliability features you expect from Windows.

To upgrade to Windows 8.1 from Windows Vista or Windows XP, you'll need to install it from a Windows 8.1 DVD and perform a clean installation. This means you won't be able to keep any files, settings or programs when you upgrade.

Visit Microsoft for the detailed tutorial.

Also read: How to upgrade Windows 8 to Windows 8.1