Change the default container for user and computer accounts in Windows Server Domain Controller
By default all Computer and Users that are added to the domain are placed in the default 'Computer' and 'Users' OU respectively.
To change the default OU for Computers, open command prompt and enter the following command:
redircmp <Distinguished Name of the new OU>
To change the default OU for Users, open command prompt and enter the following command:
redirusr <Distinguished Name of the new OU>
How do you find the Distinguished name?
Click Start > Run / Search programs and files
type MMC and hit enter
Select Add/Remove Snap-in... under the File menu
Click ADSI Edit and hit the Add button
Navigate to the location of the New OU, right click and select Properties
The distinguished Name will be displayed. Copy it and use it with the commands above.