christianhomekeeper:
Hmmm...I looked at that, thanks. But I don't think that is what is going on. When I set up the Zen Cart it sent me (emailed) my user name and password that I had set up the cart with. That's what I'm using.That may be a clue, though I'm not really sure to what. You enter your first admin username during the installation process, Zen Cart doesn't email it out to you. Additional email user names are entered via the admin settings page and again, aren't emailed out to you. So whatever you have in that email isn't you admin user name.
Do you install this yourself using the Zen Cart installer, or use an installer provided by your web host, such as Fantastico?