Did you know that the built-in Local Administrator account on your computer has a higher access level to the system than a normal local administrator account? Well, it does and by default, the built-in Administrator account is disabled for the protection of the computer and the users.
Be aware that the account can be enabled so you should verify the status in the Computer Management area at least once per week if the computer is shared. This way, you can see if someone has been tinkering around and can notify your IT Department.