I just setup my new mac yesterday. The Admin pw i chose during setup is also the login and keychain pw by default correct? There is only one account on the machine and i only want to have one account (even though one other person will be using it). If i go to system preferences and change the login pw will that automatically change the Admin and Keychain pw (since there is only one account)? I'd like the login to be different so the other person can you use the computer under my account but not make admin decisions or have access to my keychain.