The problem: I was asked by a pop-up window whether I wanted to upgrade to a new version of Ubuntu. I clicked yes, and followed prompts. I then left it to get on with its thing as it seemed to be taking a while. Unfortunately my netbook, which wasnt plugged in, ran out of battery before the installation was completed. When I next attempted to boot up Ubuntu I just get the main loading page with the dots under the word ubuntu. It never progresses from that point. I need a fix.
I realise there are existing threads on this topic but I can't understand the responses to them. If you can help me to sort this problem out then its important for you to understand that I have zero knowledge of Ubuntu or how it works. A friend set me up on ubuntu in the first place and by and large I've never had any problems so haven't had to fiddle with code. I've been running Ubuntu alongside Windows (I'm on windows now), on a split hard drive. As I can no longer boot Ubuntu I can no longer access any of the files on the ubuntu half of the hardrive.
To give you an idea of where I'm at, I have a vague idea that there's a thing called a terminal and at a push I might work out how to open it. At this point, confronted by an utterly perplexing code, I give up. I repeat, I do not know what SUDO is. I do not know anything whatsoever about commands or how they work. I'm willing to learn but I need talking through this step by step. Assume I know nothing and you'll be spot on. If someone could help me with this I would be very grateful as there are an awful lot of files in limbo which I'd dearly like to regain access to.