You may have activation and driver problems when booting on different computers. Windows 7/2008 R2 is not completely portable. Please note: 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.
Easy-to-use wizard interface that provides step-by-step instructions for creating a Windows To Go USB drive.WinToUSB supports creating a bootable WinPE USB drive, and it can help you transfer the contents of WinPE to a USB drive and make the drive bootable.
WinToUSB is a simple, lightweight application that allows you to install and run a 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.