Windows Deployment Services requires that you create two answer files instead of one to perform automated deployment. The first answer file is used for the Windows DS client when Windows PE runs, and the second answer file is used during the OOBE phase. To configure your unattend.xml file for your Windows DS client, open the properties of the Windows DS server and select the Client tab and browse to select the unattend.xml file you want to use.
The trick is when you want to use different unattend.xml files for different target machines. To do this, you need to use the wdsutil.exe utility to pre-stage them. For more information on how to do this, type wdsutil /add-device /? at a command prompt.

