I have an older desktop that I installed Xubuntu on and had it running smooth. The other day I turned on the computer to a screeching noise from the hardware and the monitor would not recognize that the computer was on. I turned the computer off then checked all cables and connections then turned it back on. I was able to get to the hp invent screen to come up that says <esc=boot menu> and so forth but cannot access anything past that screen. I can't put a new version of anything on the desktop until I can enter the BIOS. Any thoughts?