Acer Aspire 5100 compressed hard drive by accident

Hi, I'm not sure if I'm writing this in the right forum but here goes anyway. I'm not comp savvy at all, I know my basics but I accidentally compressed my hard drive on my Acer Aspire 5100 which stopped me from being able to log in to my lappy.So I seeked help via Facebook (yes I know its not the wisest choice), and someone suggested I get a recovery disc. So I got that from someone but when I installed what I though was a recovery disc, it turned out to be a windows xp disc which has wiped what I was trying to recover. I then saw that it needed an activation key which I or the owner of the disc didn't have. So.........I was shown a way to bypass the product key part but I'm having to do the bypass thing every time AND it keeps flicking back. I use to have internet until I made this stupid mistake. Can someone please tell me in dummy form, exactly what I need to do or download in order to get my laptop up and running without having to pay millions?