KB2771431 - Download Update for Windows 8 & Server 2012
This stack update from Microsoft will resolve a series of issues related windows update such as:
A Windows 8-based or Windows Server 2012-based computer experiences high CPU usage when it runs a Windows Update applicability scan. Additionally, the applicability scan takes longer than expected.
Duplicate entries are logged in the CBS log file when the Windows 8-based or Windows Server 2012-based computer runs an automatic Windows Update applicability scan.