WinToUSB is a free software that allows you to install and run Windows operating system on a USB hard drive or USB flash drive, using an ISO image or CD/DVD drive as the source of installation. In the newest version you can clone current Windows OS (Windows 7 or later) to a USB drive as a Windows To Go Workspace. WinToUSB also support creating bootable WinPE USB drive, it can help you to transfer the contents of WinPE to the USB drive and make the drive bootable.
