You can also create a Windows To Go USB drive which enables you boot and run Windows from USB drive.
ISO2Disc is another freeware tool which allows users to create a bootable USB of Windows 10, Windows 8.1 and Windows 7 from ISO files.
WinToFlash help you pull over the contents of a Windows XP, Windows 2003, Windows Vista, Windows 2008, Windows 7, Windows 8 installation disk and prepare the USB drive to become a bootable replacement for the optical drive. WinToFlash starts a wizard that will help pull over the contents of a windows installation CD or DVD and prep the USB drive to become a bootable replacement for the optical drive.