The files you include will be in the root directory of the Windows PE CD. Once you have a WinPE image to work with, you can add packages to it with DISM /add-package. Youll find boot.wim at sourcesboot.wim in your working files.
See WinPE: Create bootable media to learn how to make a set of WinPE working files that include a WinPE image. It is also possible to burn the BartPE CD with the PE Builder. Before adding OCs to a WinPE image, you need a WinPE image (boot.wim). There is also the different ones, one for Vista and one for Windows 7. from each project, and grab them all with a click on the Download button. Windows 7 (32 bit), Windows 7 (64 bit), Windows Server, Windows Vista. Winbuilder alternatives are mainly Bootable USB Creators but may also be System Cleaners or File Recovery Tools. WinBuilder 082: Create your very own custom Windows-based boot discs.
Other great apps like Winbuilder are Windows Preinstallation Environment, AppleJack, Windows Assessment and Deployment Kit and AOMEI PE Builder.
Windows Registry Editor Version adapters" The PE Builder is a very simple tool: you only have to tell it the path to the Windows installation files, folders or files you want to include, and the output directory for the ISO file. The best alternative is BartPE, which is free.