Windows 8.1 Update is the second major update for the Windows 8 operating system.

This update, previously known as Windows 8.1 Update 1 and Windows 8 Spring Update, is free for all Windows 8 owners. If you are running Windows 8.1, you must install this update to receive security patches released after April 8, 2014.

The update includes a number of user interface changes, especially for users who use Windows with a keyboard and/or mouse.

For basic information about the operating system, including system requirements, see our Windows 8 article . Check out our Windows 8.1 roundup for more information about Microsoft's first major update to this version of Windows.