If you delete all .xml files from the Vista/7/8/SVR2012 folders, then the default unattend.xml will be automatically used and the user will not be prompted to select an xml file.
Microsoft's „Windows System Image Manager“ (WSIM) is used to create autounattend.xml files, and can also validate these files against an XSD schema:
1 May 2017 Answer files (or Unattend files) can be used to modify Windows Next, select an edition of Windows, for example, Windows 10 Pro, and click