The local administrator account becomes the domain administrator account when you create a new domain. The new domain cannot be created because the local administrators account password does not meet requirements.
Currently, a password is not required for the local administrator account. We recommend that you use the net user comand-line
tool with the /passwordreq:yes option to require a password for this account before you create the new domain; otherwise, a password will not be required for the domain administrator account.
To resolve the problem:
The password for your local account needs to meet the minimum password complexity:
The password is at least six characters long.
The password contains characters from three of the following four categories:
English uppercase characters (from A through Z)
English lowercase characters (from a through z)
Base 10 digits (from 0 through 9)
Non-alphanumeric characters (for example: !, $, #, or %)
If your still having a problem, this is what you have to do to bypass dcpromo.exe Administrator Password required error
Open your command prompt and enter the following command
net user Administrator <YourPassword> /passwordreq:yes command