Sometimes you need to mount some Windows PE ISO and modify it to match your needs. For example, add your tools to bootable iso.
I will show you how mount that iso to Windows, make the required changes and unmount.
Prerequisites
Install the Windows Assessment and Deployment Kit (Windows ADK) Technical Reference, with Windows Preinstallation Environment. If you’re using the ADK for Windows 10, version 1809, you’ll have to download and install the WinPE addon after you install the ADK. Previous versions of the ADK include Windows Preinstallation Environment in the ADK installer.
Mount image
First, you need to unpack your iso file to some folder, let’s say to C:\WinPE_amd64\media. You also need to create folder where you mount the image so let’s say you also create folder C:\WinPE_amd64\mount.
Dism /Mount-Image /ImageFile:"C:\WinPE_amd64\media\sources\boot.wim" /index:1 /MountDir:"C:\WinPE_amd64\mount"
Now you just need mount the boot.wim file to your prepared folder.
Now you can make any changes what you need in folder C:\WinPE_amd64\mount.
Unmount image
Dism /Unmount-Image /MountDir:"C:\WinPE_amd64\mount" /commit
Make bootable media
MakeWinPEMedia /UFD C:\WinPE_amd64 F: