Built-in Account is a type of user account that is created during installation.
What is Built-in Account (computer networking)?
In Microsoft Windows, Built-in user account is a type of user account that is created during installation. All computers running Windows 7 or Windows 10 have two built-in user accounts:
- The Administrator account: Used to provide administrative access to all features of the operating system
- The Guest account: Intended to provide occasional users with access to network resources
Depending on whether the computer is a domain controller, a member server, or a workstation, built-in accounts will be either local user accounts or global user accounts. A built-in account on a domain controller is a global user account that exists everywhere within the domain.

Users can log on to any machine in the domain using such an account, which provides administrators with the capability of administering a Windows NT–based or Windows 2000–based network from anywhere on the network.
On a member server or workstation, the Administrator and Guest accounts are local user accounts and exist only on those machines.
Rename the Administrator Account
Rename the Administrator built-in user account to make it more secure.