Update 2 to Windows 8.1? It’s called the August update

Windows 8.1 August Update is the official name of Update 2 for Windows 8.1, distributed with code KB2975719 (for 64-bit systems). 

New features are limited to bug fixes, a simplified registration process for SharePoint, improvements to support Miracast, and the precision of the touch panel, which now works like a mouse. 

Windows 8.1 August Update is offered via direct download or via Windows Update. To install the update, you must have Windows 8.1 Update 1.