That means that it can't find a device (internal or external hard disk or SSD, USB-stick, CD- or DVD-reader) to boot from. So it tries to find a bootable something on your Ethernet connection and that fails also.
Generally, replacing the hard disk or the motherboard is the solution, if you want to run Windows. For Linux you can use a USB-stick or a DVD, provided it's the hard disk that's broken.
My computer is stuck on the screen here: https://imgur.com/a/M1j8JBR whenever I try to boot it up. I'm not sure what this means, could someone tell me what is wrong?