Please explain what icons you need for your purposes, because all Windows icons are freely available on the Internet in large libraries of icon sets. Moving a copy of a dll will break the chain of dll's, there are references inside a dll to other dll files and when you move a dll, that reference goes to the wrong location, because it is relative to the original file
That file contains source code mainly and other resources, like icons that software on your PC use for their functionality and the names of those dll's make sense to programmers, because thy are the ones that link into those files, those files are not meant for use by the normal user.