WinPE is a useful tool for booting a computer and laying down a new operating system.  In this post, I’ll show you how to make WinPE a little more useful by automatically running a custom script at startup.

Generate WinPE File Structure

On your Windows 10 machine, make sure the Windows 10 ADK is installed.  Then, open the Deployment and Imaging Tools Environment command prompt as an administrator.

Run the following commands to create the WinPE files.

copype amd64 C:\WinPE

Next, mount the WinPE files to a folder so you can copy over your custom script (I’ll show you later on how to make a custom script).

Dism /Mount-Image /ImageFile:"C:\WinPE\media\sources\boot.wim" /index:1 /MountDir:"C:\WinPE\mount"

Customize WinPE

Delete the existing startup script and copy over your custom script.

del C:\WinPE\mount\Windows\System32\StartNet.cmd 
copy StartNet.cmd C:\WinPE\mount\Windows\System32\

Creating An Auto-executing Script

First, you need to create a file named StartNet.cmd.  The first line of your script will need to be

winpeinit

This initializes WinPE so you can run other commands.  When you are done with your script, you should shutdown or restart the computer.

wpeutil shutdown wpeutil reboot

My script below deploys a Windows 10 image to the computer.  Details on this will be in another post.

Add A Custom Background

Building Your Background Image

Space on WinPE is limited because it is loaded into memory.  I have found that there seem to be some size limitations on this file.  One that seems to work well is 1024 x 768 resolution and around 30K in size.  Feel free to use this Photoshop file as a basis.

Replacing The Background Image

For whatever reason, Microsoft doesn’t seem to want you to change their default blue background because they really locked down the permissions on this file.  You first need to take ownership of the file and then grant yourself Full Control access before you can even delete it.

Rather than clicking through all those dialogs, I suggest downloading SubInACL.exe so you can change permissions from the command line.

Take ownership of the file and grant Full Control (you can also substitute %COMPUTERNAME% in place of %USERDOMAIN% if you are using a local account).

"C:\Program Files (x86)\Windows Resource Kits\Tools\subinacl.exe" /file C:\WinPE\mount\Windows\System32\winpe.jpg /setowner=%USERDOMAIN%\%USERNAME% "
C:\Program Files (x86)\Windows Resource Kits\Tools\subinacl.exe" /file C:\WinPE\mount\Windows\System32\winpe.jpg /grant=%USERDOMAIN%\%USERNAME%=F

Delete the existing background image and replace it with your own

del C:\WinPE\mount\Windows\System32\winpe.jpg 
copy winpe.jpg C:\WinPE\mount\Windows\System32\

Save Your Changes To WinPE

Apply your changes (make sure you exit out of the folder in Windows Explorer otherwise the image will fail to unmount)

Dism /Unmount-Image /MountDir:"C:\WinPE\mount" /commit

Make A Bootable WinPE CD With Your Custom Settings

Make a bootable .iso file from your custom WinPE setup

MakeWinPEMedia /ISO C:\WinPE c:\WinPE\WinPE.iso

You should find your .iso file in the C:\WinPE directory

Burn this .iso to a CD and you can boot up a computer and have it automatically run your script.