I found a great article made by Alastair (Professional VMware Blog) about using AutoLab to make Windows Unattended Core Instalations:

Windows unattended install

Microsoft have been very good at providing unattended install methods for Windows, with Windows Server 2008 the “answer” file is in XML format.  The official tool to generate the answer file is the Windows System Image Manager (WSIM) tool, a part of the Windows Automated Install Kit (WAIK) which is a large download as it includes WindowsPE.  The overview and lots of additional information is here on the TechNet web site. Of course there are plenty of samples of unattend.xml files on the Internet along with lots of suggestions of snippets that do things.

One of the tricks we use in the AutoLab is to place the answer file on a floppy and boot from a normal Windows install ISO, I haven’t seen this method described anywhere but it works really well for us.  The xml file is named autounattend.xml, rather than the default unattend.xml, as this lets the installer know not to seek confirmation of things like repartitioning the boot disk.  The answer file covers the TCP/IP setup as well as local accounts, autologon for the console, disabling the firewall, installing optional services and removing most of the out of box experience.

The answer file includes a directive to autologon once Windows is installed and  a script to run on first startup of the installed copy of windows. At the moment this script is pulled from the boot floppy, in the next release it will come direct from the build share.  The initial script is kept short, it transfers control to the script on the build share as early as is practical.  Each Windows server has a folder on the build share under the Automate folder, this is used to hold everything specific to the Windows server and that can be distributed with the AutoLab kit.  Only small and freely redistributable software is included with the kit and we try to minimise.


See more details about this at Professional VMware Blog