Have you tried the last step (installing and using Firefox)? That one usually solves the problem.
Additionally, what kind of message do you get when it logs you out?
It doesnt say anything it just refreshes. I am not allowed to install anything. I was able to log in on my computer before I went inactive about 6 or 7 months ago.
If you have not tried installing Firefox, then you should not say you have tried all the steps, because that is the one, as Togan pointed out, that typically solves the problem. If you are unable to do that, you will be stuck waiting around here indefinitely until Khan can try to look into it, but even then there are no guarantees that he will be able to resolve it.