Compact OS, single-instancing, and image optimization

 CompactOS

Windows 10 includes tools to help you use less drive space. You can now compress the files for the entire operating system, including your preloaded desktop applications. Compact OS lets you run the operating system from compressed files (similar to WIMBoot in Windows 8.1 Update 1), and single-instancing helps you run your pre-loaded Windows desktop applications in compressed files. The new processes helps maintain a small footprint over time by using individual files, rather than combining them in a WIM file.

 

You can query whether the operating system is running Compact OS, and change it at any time, using the Compact.exe command.

From Windows PE, determine if the OS is compacted:

Compact.exe /CompactOS:Query /WinDir:E:\Windows

Where E:\Windows is the folder where Windows has been installed.

From an online installation, change from non-compacted to compacted OS:

Compact.exe /CompactOS:always

Reference - https://docs.microsoft.com/en-us/windows-hardware/manufacture/desktop/compact-os