Resetting administrator

I've got a imac desktop with Tiger os and, for some reason, I can only access one of the user accounts that has the status of "restricted" or whatever the minimal access user setting happens to be. I do not remember the password/nor the name of the administrator name either. On top of that, I decided that just wiping the os off the computer and starting over would be a good idea, until i remembered that my CD drive was broken. Short of going and getting a new one, would anyone know how to reset the administrator under my circumstances? thanks

You need either a clean install, or to be able to boot up from the restore disk to reset an admin password