I recently started using Ubuntu regularly, as it ran much more efficiently than Windows 7 which I'd been using before. I'm not the most knowledgeable person when it comes to computers, so I can't go into detail about what went wrong, as I don't fully understand, so let me try to explain step-by-step.
I had downloaded and installed Ubuntu 12.04 64-bit using the Wubi windows installer, and it ran just fine. I got all my files moved/copied over and 'set up shop' so to speak. After about a week, I tried to upgrade to 12.10, so I let the update go, making sure everything was closed, and checking yes to pretty much every box that came up. After I hit yes to the "Delete outdated files" option, or something along those lines, it was almost finished with the process when it asked me if I wanted to restart my system. I did. Then after booting up again, my screen just went black. In the top-left corner there was an underscore like I could type something, but it appeared to be frozen. I would greatly appreciate if someone could find out what went wrong, and hopefully tell me how to fix it.