The common USB flash drives are very slow.

Windows 7 does not have built-in USB 3.0 support, so Windows 7 will have to be booted from a USB 2.0 port. You may have driver problems when booting on different computers, so highly recommend using Windows 11/10/8.1/8 to create portable Windows.

Clone current Windows OS which on a USB disk (Windows To Go USB drive) to other USB drives as a Windows To Go Workspace Clone current Windows OS which on a dynamic disk to a USB drive as a Windows To Go Workspace Clone current Windows OS (Enterprise edition of Windows 10/8.1/8/7) to a USB drive as a Windows To Go Workspace Creation of Windows To Go on Non-Certified Windows To Go USB Drive. Use of a Non-Enterprise Edition of Windows 10/8.1/8/7 to create Windows To Go Workspace. Clone an existing Windows OS (Windows 7 or later) to a USB Drive as a Windows To Go Workspace. Creation of Windows To Go from an ISO image file or CD/DVD drive. Easy-to-use wizard interface that provides step-by-step instructions for creating a Windows To Go USB drive.

WinToUSB also supports creating a bootable WinPE USB drive, it can help you transfer the contents of WinPE to a USB drive and make the drive bootable. Starting from version 2.0, you can clone current Windows OS installation (Windows 7 or later) to a USB drive as a Windows To Go Workspace. WinToUSB is the best Windows To Go Maker 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. WinToUSB 7.1 Release 2 Technician Multilingual Portable | 29.8 Mb

Wintousb for mac os