By default, new computers are placed in the on a container called "Computers" as opposed to being placed in an Organizational Unit. OUs have the advantage of having Group Policy supplied to them. Take this example:
You have Windows Software Update Services servers located in each of your geographically dispersed offices. Using Organization Units, you have divided up the client by site and used Group Policy to direct them to their local WSUS server. You add a new computer to your domain. Will it be told where to find its WSUS server? Most likely not. You must first move it to an OU that had a GPO assigned. Then end result could be security configurations that are not applied to the client. By redirecting where the new computer accounts are created in Active Directory, you can make sure that the new client is brought online in the most secure fashion possible.
Below is the step by step procedure copied from the reference link at the end of this article. The redircmp command is part of windows and does not need to be downloaded.
Redirecting CN=Computers to an administrator-specified organizational unit
1. Log on with Domain Administrator credentials in the domain where the CN=computers container is being redirected.
2. Transition the domain to the Windows Server 2003 domain in the Active Directory Users and Computers snap-in (Dsa.msc) or in the Domains and Trusts (Domains.msc) snap-in. For more information about increasing the domain functional level, click the following article number to view the article in the Microsoft Knowledge Base:
322692 (http://support.microsoft.com/kb/322692/ ) How to raise domain and forest functional levels in Windows Server 2003
3. Create the organizational unit container where you want computers that are created with earlier-version APIs to be located, if the desired organizational unit container does not already exist.
4. Run the Redircmp.exe file at a command prompt by using the following syntax, where container-dn is the distinguished name of the organizational unit that will become the default location for newly created computer objects that are created by down-level APIs:
redircmp container-dn container-dn
Redircmp.exe is installed in the %Systemroot%\System32 folder on Windows Server 2003-based or newer computers. For example, to change the default location for a computer that is created with earlier-version APIs such as Net User to the OU=mycomputers container in the CONTOSO.COM domain, use the following syntax:
Note When Redircmp.exe is run to redirect the CN=Computers container to an organizational unit that is specified by an administrator, the CN=Computers container will no longer be a protected object. This means that the Computers container can now be moved, deleted, or renamed. If you use ADSIEDIT to view attributes on the CN=Computers container, you will see that the systemflags attribute was changed from -1946157056 to 0. This is by design.