I sometimes get this problem with USB sticks regardless of the tool I use to write the image. I have one machine where I seem to get disk signature collisions so Windows sets the USB stick to offline. This seems to happen when it's plugged into a USB3 port. If I plug it into a USB2 port on the same machine, there are no problems and I can access the config file. If you open up Disk Manager, you should be able to see the USB stick regardless of whether it shows up as a drive you can access. If it's set to Offline mode you can try to set it to Online mode. If it won't go online, it will give you an error and tell you why. If it says there is a disk signature collision, try plugging it into a USB2 port or a different machine. I don't have this problem at all on a different Windows machine so try another machine if you have access to one.