WinToUSB (also called Windows To USB) is the best free Windows To Go Creator which allows you to install and run a fully-functional Windows on an external hard drive, USB flash drive or Thunderbolt drive. It is so easy and efficient, with just a few simple steps and a few minutes, you can create your first portable Windows 11/10/8/7/Server (2008 or later) directly from an ISO, WIM, ESD, SWM, VHD, VHDX, DBI image file or a CD/DVD drive, or you can use it to clone an existing Windows 11/10/8/7/Server (2008 or later) installation to a USB drive or Thunderbolt drive as portable Windows. WinToUSB also supports creating a Windows installation USB drive from a Windows 11/10/8/7/Server (2008 or later) installation ISO. 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 or Thunderbolt drive.
Creation of Windows To Go from an ISO/WIM/ESD/SWM/VHD/VHDX image file or CD/DVD drive.
Creation of WTG from system backup image produced by Hasleo Backup Suite.
Clone currently running Windows OS (Windows 7/Server 2008 or later) to a USB or Thunderbolt drive as a Windows To Go Workspace.
Use of a Non-Enterprise Edition of Windows 11/10/8.1/8/7 to create Windows To Go Workspace.
Support for creating VHD-based/VHDX-based Windows To Go Workspace.
Creation of Windows To Go on Non-Certified Windows To Go USB Drive.
Encrypt Windows To Go with BitLocker to keep your data safe.
Clone Windows between disks with different sector sizes.
Support for creating portable Windows for Intel-based Mac computers.
Support for creating Windows installation USB drives.
Support for creating bootable WinPE USB drives.
Support for downloading official Windows 11/10/8.1 ISO file from Microsoft.