Shrinking Windows 10

After a clean install of Windows 10 LTSC, I get about 11 GB of free space on a 32GB eMMC. Given that there are no crapware that comes with LTSC, there is not too many options on reducing the footprint of the operating system.

I started off by turning on NTFS disk compression a.k.a. "Compress this drive to save disk space". Windows started compressing each and every file on the drive. After an hour of processing, it's still at it. Strangely enough, I didn't see the progress bar updating, so I clicked on the Cancel button. The compress option is still checked/enabled, so I'm guessing the system will continue compressing files in the background. (I hope.) I did recover about 1 GB of space, so not too shabby.

Next option is Compact OS. This basically compresses the system files of a running Windows installation.

Microsoft Windows [Version 10.0.17763.1158]
(c) 2018 Microsoft Corporation. All rights reserved.

C:\Windows\system32>compact.exe /compactos:query
The system is not in the Compact state but may become compact as needed.

C:\Windows\system32>compact.exe /compactos:always
Completed Compressing OS binaries.

45819 files within 23290 directories were compressed.
10,110,547,923 total bytes of data are stored in 5,648,116,616 bytes.
The compression ratio is 1.8 to 1.

C:\Windows\system32>

From 11 GB of free space to 16 GB - pretty good.

Turned off the hibernation feature, which effectively deletes the hiberfil.sys file, for another GB of free space.
C:\Windows\system32>powercfg /h off

Another option to try is turning off System Protection under System Properties, which disables the creation of regular restore points. Looks like this is the default option in LTSC.