I have a lenovo 3000 J series that was running Ubuntu 12.04. I wanted to upgrade to the most recent supported version of Ubuntu, but read that I need to do so one step at a time and that the first step would be from 12.04 to 12.10.
I followed the instructions from this website:
and launched the update manager.
I clicked through everything and reached the end when the computer was to restart. When it did, it began normally with messages like "verifying pool", but then after it displayed "ubuntu" and said "checking", the screen started to flash. There was no more text, nothing for me to select. I let this go on for several minutes until I forced the computer to shut down. I restarted it a few more times but got the same result.
How can I get this computer working again? Ideally I'd like to get to the most recent, most stable version of Ubuntu, but anything that works would be an improvement.