I think my installation of ubuntu is stuck. I am installing from usb to a computer with windows. I made an iso, burned it with unetbootin(but this program is bad, I was getting a "no operational system found" and "no bootmrg" messages when I was selecting the usb. My lastes usb was made now with rufus. I choose my usb drive, see an ubuntu logo, then some code goes fast, and now nothing is happening I just got the black screen with an underscore.