Add the RunSynchronousCommand items to the specialize section of the custom sysprep.xml file:<?xml version="1.0" encoding="utf-8"?><unattend xmlns="urn:schemas-microsoft-com:unattend"><settings pass="specialize"><component name="Microsoft-Windows-Deployment" processorArchitecture="amd64" publicKeyToken="31bf3856ad364e35" language="neutral" versionScope="nonSxS" xmlns:wcm="" xmlns:xsi=""><RunSynchronous><RunSynchronousCommand wcm:action="add"><Path>C:\sysprep\guestcustutil.exe restoreMountedDevices</Path><Order>1</Order></RunSynchronousCommand><RunSynchronousCommand wcm:action="add"><Path>C:\sysprep\guestcustutil.exe flagComplete</Path><Order>2</Order></RunSynchronousCommand><RunSynchronousCommand wcm:action="add"><Path>C:\sysprep\guestcustutil.exe deleteContainingFolder</Path><Order>3</Order></RunSynchronousCommand></RunSynchronous></component></settings></unattend</FONT>>
Note: If the custom sysprep.xml answer file contains other RunSynchronousCommand items, add the values in order, after the existing RunSynchronousCommand items in the sysprep.xml answer file.