And me from Sweden
If you arnt accustomed to working with them, ISO files seem a bit mysterious at first. That's because they contain a complete representation of a disc.
Within the ISO file are all the folders and files found on the disc, as well as the glue that holds the disc together. In the good old days, people would take an ISO file and burn it to a CD or DVD, nowadays ISO files are frequently burnt to a USB drive so you can boot from them.
There are a number of ways to create bootable USB drives, The Windows Media Creation Tool if you download the Windows ISO from Microsoft is one way but if you have other media that is in ISO then you need to turn it into something that can be booted.
Rufus comes from Akeo Consulting in County Donegal, Ireland. Its free and open source. It does one job only and that job is to turn an ISO into a bootable drive.
If you burn ISO's to Bootable USB's then give this a try.