Windows NT Version 6.x (Windows Vista, Windows 7, Windows 8, Windows 8.1, Windows
Server 2008 and Windows Server 2012) requires special steps to allow you to use local
Windows administrator accounts.
Procedure
Open Computer Management.
Open the Start menu.
Right-click Computer.
Go to Manage.
The Computer Management window appears.
In the list on the left, go to Computer Management → System Tools → Local Users and Groups → Users.
The list of local Windows user accounts displays.
In the list of user accounts, right-click Administrator, then go to Properties.
The Administrator Properties window appears.
In the General tab, clear Account is disabled.
Click OK.
The Computer Management window reappears, displaying the list of local Windows user accounts.
Right-click Administrator, then go to Set Password....
A message displays instructions for setting the password.