If burning the .iso files with MultiSystem or UNetBootIn does not install the system completely, or the computer does not recognize it, with this small tutorial you will recognize any ISO.

The first thing we need is to download the ISO that we want to burn and have it properly located in our system, for example in the Downloads or Documents folder.

In addition we will have to mount a USB in format FAT32 in our system.

To burn the ISO we must open a terminal (Ctrl + Alt + T) and execute the following command:

sudo dd if=/ruta/al/archivo/iso |pv|dd of=/ruta/al/usb bs=1M

NOTE: do not confuse if and of, because we can keep an iso of the same size as the USB and we would have to download the iso system again.

Below is a real example. This process will last a while, the terminal should NOT be closed, in the end a resume will appear that has finished correctly, as shown in the image below.

sudo dd if=/home/user/Descargas/ubuntu-18.04.iso |pv|dd of=/dev/sdb bs=1M

Note: The path to USB has been set, not the partition, because if so, the USB could not start

Another option is to put it like this:

sudo dd bs=4M if=/home/user/Descargas/ubuntu-18.04.iso of=/dev/sdb status=progress && sync

Once done we will have our USB ready to install the system that we have previously downloaded