If this is the tool you are talking about (see attachment)
Then the contents of the bootable USB device should look like this. (see other attachment)
As far as why it won't boot from the device you might want to try one of the F-Keys during post, sometimes F11, but can vary based on make and model of your particular computer but you may see it noted on the post screen as press F11 to select boot device or words to that affect.