Why can't I log onto my computer?

Earlier today, I had to get my school computer wiped out because I had to update a software. I went home and when I tried to log on, it told me there wasn't any log on servers available. It said I was logging on to my school domain which is only available when Im at school. It told me to type 2012-TRA0025/ local user name but i dont know what my local user name is. How do I log in without having to log in as an admin? Thanks