During a migration of info from a time machine backup into my new mac mini, I got the "less than one minute left" hangup. On restarting, I found myself as a guest only-- my admin. name and password disappeared and I am locked out. That is, I can enter as a guest, but I am constantly asked for administrator name and password, and what I enter is not recognized, so I can't get anything done. As owner, or administrator, I am locked out.