ImageUSB facilitates concurrent image writing to multiple USB Flash Drives along with also permitting the creation and mass duplication of exact bit-level copies of USB Flash Drive (UFDs).
Unlike other USB duplication tools, ImageUSB can preserve all unused and slack space during the cloning process, including the Master Boot Record (MBR).
Warning: Due to the forensic nature of image duplication by ImageUSB, please ensure that you select UFDs with a storage size similar to the image you wish to duplicate. For example, if a 2GB image is copied to an 8GB USB Flash Drive, the drive will only be able to use two out of the eight gigabytes of storage space. In this scenario, users will need to reformat the UFD to access the rest of the storage space.
Rufus is a small Open Source utility that helps quickly format and creates bootable USB flash drives, such as USB keys/pen drives, memory sticks, etc. Rufus is now integrated with Fido to download Windows 10 and 8.1 ISOs from Microsoft servers. Video guide available.
WinToUSB will install and run the Windows operating system on a USB hard drive or USB flash drive, using an ISO image or CD/DVD drive as the installation source.