how can i hadle a badtrip office mate?

Maybe you need to sit down and have a chat. I have once seen a situation a bit like this, 2 people had equal jobs but one kept telling the other what to do and was correcting them all the time which made the other mad as they didn't see that someone with the same position as them had the right to boss them around. Is it possible that this person feels like you are picking on them rather than trying to help and that is what is annoying them? Since you say co-worker, I am assuming you are not this persons boss? Maybe the best thing to do is to sit down and have a discussion and try to clear the air with this person in the interest of having a better working relationship??