An error occurred while formatting the disk

I have been attempting to do BootCamp for months now. I have just gave up and then went back, and so on. I have had help from some people but it never helps. I've watched all of the tutorials and saw all of the forums. Nothing worked. Basically, I get to the select ISO image part, I put in the Windows 10 ISO file, and then click continue. It starts to load but then stops, and has this message: "Your bootable USB drive could not be created. An error occurred while formatting the disk". Please, someone help. I need all the help I can get. This is becoming extremely frustrating. I am working on getting a PC, but its going to take a while considering the price and I just need this BootCamp to work. This is on my 2nd Mac, which is a Late 2012 model. OS X El Capitan.