I'm thinking he might be happier with Noridian, ZephyrOS, Sylvanix, or AetherForge.
I myself have been trying neoNova, specTRAos, and VortexLinux and they're all pretty good.
...
All of these are made up, I think, I just can't cope with everybody and their dog still rolling their own distros (and alternatives to GNOME 3, thank goodness for KDE), even after 25 years of observing it happen over and over again.
And then try
DISM.exe /Online /Cleanup-image /Scanhealth
andDISM.exe /Online /Cleanup-image /Restorehealth
that'll get rid of the 9GB file for sure. If not, reinstall everything again and again and again.