by boco » 24.05.2017, 20:08
Ah, yes, those. Placeholders. WOU uses commandline downloaders (like wget) to get the files. It refreshes the static definitions by downloading them from this site. That prevents the need to release a new version, every time static links change.
The important thing to know is: wget can only download, it cannot delete. So, the only way to effectively kill a file (that previously might have had contents that are now obsolete) is to download an empty file over it.
Otherwise, no file or zero-Byte file makes no difference.
Note that all static definitions will be refreshed, independent from your actual OS selection.
Follow-up: There's also a historical reason for placeholder files in archives: Some unpackers won't restore empty directories unless there is at least one file inside it. So, if restoring the directory structure is important, placeholders will ensure all directories are extracted.
Microsoft update catalog: http://catalog.update.microsoft.com/v7/site/
Windows Install media download: https://support.microsoft.com/en-us/help/15088/windows-create-installation-media