Download the Windows 8.1 update from the Microsoft Download Center
If you cannot download and install the new Windows 8.1 Update using Windows Update, even if you have configured Windows 8 to automatically download and install updates, you can download and install this Windows 8.1 update package from the Microsoft Download Center. Download and install Windows 8.1 Update, 32-bit and 64-bit if you receive error codes 80070020, 80073712 and 0x800f081f and if Windows 8.1 Update cannot be installed, download and install it via Windows Update.
The Windows 8.1 update is a cumulative set of security updates, critical updates and updates and introduces new features. In addition to previous updates, it includes enhancements such as improved Internet Explorer 11 compatibility for enterprise applications, improved usability, advanced mobile device management and improved hardware support. In Windows Server 2012, this package also supports host clustering configurations.