An alternate option to using BartPE is to download the WAIK or ADK from Microsoft, install it onto a machine, and within the Help Files are walkthroughs on how to create a bootable WinPE image, which can be used either as a .ISO or a USB image.
Of course, you will need a Windows7/Windows 8/Windows Server 2008 R2/Windows Server 2012 DVD that the process will use to copy the necessary files from to create the WinPE image.