by boco » 20.12.2012, 00:25
Not recommended, since old, deprecated and superseded updates won't be removed that way, leading to a cluttered, bloated repository on the stick. But yes, you need only copy changed files, as these include the new catalog file the updater uses.
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