How to Make a Boot USB From an ISO
Operating systems are digitally distributed as ISO files. An ISO is an exact image of an installation disk and may be mounted on a USB flash drive. In order to properly use the mounted ISO, the flash drive must also be made bootable so that your computer will boot into the flash drive instead of its hard drive.This process is fairly quick and painless using a free utility.
Download a free utility for ISO conversion. One such example is WinToFlash (a link is provided under Resources).
Insert your USB drive into your computer.
Run the application.
Select the "Basic Parameters" tab. Set "USB Drive Type" to "Flash Stick." Set the "Format" to "USB-HDD." Set the "File System" to "Fat32."
Under "Windows Source Path," navigate to the ISO image file you would like to make bootable.
Navigate to your USB flash drive under "USB Drive." Select "Run" to begin the process. In under 10 minutes, you will have a fully bootable USB drive with your new operating system on it.