Created New User Account / Now Desktop All Messed Up

My computer was working fine. I would turn on the computer and it'll go straight into my desktop and I'll see all my files and icons on the desktop. Just 2 days ago, my son decides to "create" his own user account and he happens to set it him up also as the "administrator". When ever we turn on the computer, it would go to a screen and it would ask us to select a user to log on as (only one avail, it's his). We'd click his user account and it goes to a desktop, however, there is only 2 icons (recycle bin and adobe reader), nothing else. Where are my files/icons? How do I fix it? I rather undo what he did but it appears that I can't delete his user account because he is the administrator.