I want to put back my original Xbox dashboard, and then start over agian. The bad thing is, is that I forgot to backup. Is there a way to get the original retail xbox dashboard back onto my Xbox, and then delete the softmod and start over?

depending on how you softmodded it, assuming you used an installer, you should have an option to remove it by running the installer again.

Okay, but what will happen, because I haven't backed up anything?