WinToUSB (also called Windows To USB) is the best free Windows To Go Creator that allows you to install and run Windows operating system on an external hard drive or USB flash drive, using an ISO/WIM/ESD/SWM/VHD/VHDX image file or 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. Oh, WinToUSB also supports creating a bootable Windows PE USB drive, it can help you transfer the contents of Windows PE to a USB drive and make the USB drive bootable. WinToUSB's key features include: Easy-to-use wizard interface that provides step-by-step instructions for creating a Windows To Go USB drive. Creation of Windows To Go from an ISO/WIM/ESD/SWM image file or CD/DVD drive. Clone an existing Windows OS (Windows 7 or later) to a USB Drive as a Windows To Go Workspace. Use of a Non-Enterprise Edition of Windows 10/8.1/8/7 to create Windows To Go Workspace. Creation of Windows To Go on Non-Certified Windows To Go USB Drive. Support for creating VHD-based/VHDX-based Windows To Go Workspace. Support for creating Windows installation USB drives. Important notes: Windows 7/2008 R2 does not have built-in USB 3.0 support, so Windows 7/2008 R2 will have to be booted from a USB 2.0 port. USB flash drives are very slow. It takes a long time to install and run Windows from a USB flash drive, highly recommend using a USB hard disk. Windows To Go drives can be booted on different computers, so you can carry it to anywhere and use it on any computer. Windows 7/2008 R2 is not completely portable. You may have activation and driver problems when booting on different computers.