That's not so much the problem as that there is an account, pre-installed on the machine, that is named "Administrator," which I can't seem to change the name of, change the status of, or delete.
The way I understand the workings of this account, it should not show up under normal circumstances on the welcome screen if there is another account with administrative privileges.
However, not only is "Administrator" visible, but it is also automatically logged in upon startup, bypassing the password assigned to the account and posing a significant security risk.