Updated: The procedure also works with Windows PE 4 / 5.
You will see that the procedure described here is much more convenient and easier than most solutions you'll find on the internet. In this article, I will describe how you can create a bootable Windows PE 3.0 (WinPE) CD/DVD or USB flash drive.
The Windows AIK for Windows 7 must be installed on a PC running Windows Vista or Windows 7. Windows PE 3.0 is the newest version that can be created using the Windows Automated Installation Kit (AIK) for Windows 7. Windows PE can be used for deploying, testing and repairing Windows installations, or as a recovery CD/DVD for system administrators.