I have a laptop that I have been dual booting Windows 8 and Ubuntu on for over a month now, but for some reason Ubuntu has stopped booting. Upon powering up the computer GRUB shows up and displays the operating systems as it always has, but when I select Ubuntu I get a black screen with a flashing underscore cursor. I have been racking my brain for causes, but I cannot figure it out. It was working, then it wasn't.
First I tried using the "recovery mode" to fix any issues, but I couldn't even get it to boot into recovery mode. Although I admittedly do not know what was being output to the screen, it kept hanging up on at different points (the numbers ranged from 18 to 100) and the errors read something like "unfriendly input/output error". I tried using the "boot-repair" live CD with no avail. I think one of the primary issues was simply that I couldn't get my computer to connect through the internet even while using an Ethernet cable. I am re-downloading the Ubuntu CD now with the intent of trying to download and install boot-repair as instructed here:
Any insights as to what caused this or what is wrong? Also, will the boot-repair utility actually repair the damage that has been incurred?