Microsoft-made themes are formatted like this:
[name of theme] (folder)
- DesktopBackground (folder)
- [backgrounds].jpg
- icon.jpg
- [name of theme].theme
- [audio files].wav
The problem is, if they're all in the same folder in Windows\Resources\Themes, the file names conflict.
I'm making an ISO with everything Microsoft made. All language packs, all updates (2009-2020), and every other "miscellaneous" thing that Microsoft had at some point.