Download Windows Assessment and Deployment Kit (ADK) for Windows 8
Windows Assessment and Deployment Kit (Windows ADK) is a collection of tools that you can use to customize, assess, and deploy Windows operating systems to new computers. In brief, it means you could customize your own OS as well as create a Windows PE bootable CD with AOMEI Partition Assistant.
Download Windows Assessment and Deployment Kit (Windows ADK)
Version Platform Size Link
PE4.0 for Windows 8 Windows 8/8.1, Windows Server 2012, Windows Server 2008 R2 2.5GB Download from Microsoft Download Center

Note: To install Windows ADK, you could click here for reference (the steps like installing Windows AIK).