WinToUSB (also called Windows To USB) is the best free Windows To Go Creator which allows you to install and run fully-functional Windows operating system on an external hard drive or USB flash drive, using an ISO, WIM, ESD, SWM, VHD, VHDX image file or a CD/DVD drive as the source of installation, or you can clone current Windows OS installation (Windows 7 or later) to a USB drive as a Windows To Go Workspace. WinToUSB also supports creating a Windows installation USB flash drive from a Windows 10/8.1/8/7/Vista/2008/2012/2016 installation ISO file, so you can install Windows from the USB flash drive easily.
Windows To Go Creator allows you to install and run Windows on an external hard drive or a USB flash drive, then you can carry this portable Windows USB drive to anywhere and use it on any computer.
WinToUSB releases a feature called "Windows Installation USB Creator" which allows you to create a Windows installation USB drive from a Windows 10/8/7/vista/2016/2012/2008 installation ISO image file with a few simple steps, with this feature you can create a Windows bootable USB drive to install Windows on both Traditional BIOS and UEFI computers by using the same USB drive.
WinToUSB also supports creating a bootable Windows PE USB drive, it can help you transfer the contents of a Windows PE image to a USB drive and make the USB drive bootable.