Roland Janus provided a wonderful write-up on how to Pre-Stage a wim file in your task sequence for locations where you need to reduce network traffic and deployment reliability.  However, one caveat is that midway through the implementation, one needs to make the task sequence a “required” deployment or else the deployment will not continue to the second phase, after the WIM was laid down.  This was no good for my environment of over 10,000 workstations.  Setting a deployment as “required” and passing control out of our hands to the wims (no pun intended) of SCCM was not an option, no matter how reliable it was.

To get around this, we can leverage the functionality to have an available (but hidden) PXE boot task sequence and a prestart command on the .WIM file to choose the hidden task sequence and continue Windows refresh.

1. Implement Roland’s solution all the way, you will end up with one “required” task sequence.
2. Change the task sequence to an “available” one so you get back that control.  Split the task sequence into two task sequences at the point of “Reboot”.  The Reboot step should be the last step of the first task sequence.

   

3. Now with two separate task sequences, how do we ensure that after the “Reboot” of the first task sequence, the workstation will step into the 2nd (Step 2) task sequence?  First, we need to make the 2nd (Step 2) TS available  but hidden, so that people don’t trigger it accidentally.  Find the deployment ID of the Step 2 task sequence and keep it handy for the next step.
4. Download the get_SMSTSPreferredAdvertID_via_Prestart.vbs and edit it by popping the deployment ID in there.  Create a package with this .VBS file as the content, no program is required.  We will use this package in #8.
5. So now we are all set to make the magic happen when you create the PreStaged task sequence media .WIM file.  On the first screen, ensure that you check off “Allow unattended operating system deployment”, as if we are booting to a “required” deployment which we are not.
6. Make sure you don’t check off “Protect media with a password” or else it will prompt the workstation and the deployment won’t be zero touch.
7. Select your Step 2 task sequence with all the package and driver goodies you want if you want to save on network traffic.
8. In the last step of creating the media “Customization”, check off “Enable prestart command”.  Use the command cscript.exe get_SMSTSPreferredAdvertID_via_Prestart.vbs to call the VBS.  Include the files for prestart and point it to the package you made in #4.  This is the key step as it will force the workstation to step into the Step 2 task sequence after it reboots to finish the rest of the Refresh deployment.

Now you are all set.  Trigger the first Refresh task sequence via Software Center or a script.  It will automatically step into the second task sequence after laying down the prestaged WIM and rebooting.  Both task sequences are “Available” instead of “Required” leaving you the control of when to deploy your Windows 10 Refresh.