How to delete an administrator account (Windows 8)?

I use Windows 8 with Windows 7-like GUI, classic shell

I have two administrative accounts: user and Administrator.

I am currently user

Control Panel\All Control Panel Items\User Accounts\Manage Accounts\Change an Account does not show "Delete" button:

I run cmd with administrative privileges and executed

net user Administrator /active:no

net user Administrator [/DELETE]

Both times I got "The command has completed successfully" message, but Administrator is still visible under Manage Accounts menu.

When I execute these commands again, I get the same message.