With the end of support of Windows XP, many costumers want to join them to their domain to enforce security on it before finishing the deployment of newer Windows operating system.As you may know, Windows XP, by default, event SP3, does not have “NetDom” binaries. You can have it if you install the Windows XP Support Tools, but if your computers are in a WorkGroup, software deployment aren’t an easy task.
So, you can use the “Add-Computer” cmdlet from a Windows Server 2012 in the target domain, or you can use NetDom from a Windows Server 2003 and newer by specifying the local credentials as well as domain credentials:
netdom join WindowsXP /domain:OldForest.com /UserD:Administrator /PasswordD:PassWord /UserO:Admin /PasswordO:PassWord /REBoot
More parameters are available with “NetDom /?”.
Note : If you plan to join your Windows XP boxes to a domain with RODC schema preparation you want to consider this :