I think this is what you are looking for. If not, please provide more details like Encore version, operating system, etc
That is one of two good links.
There are 2 different library download/install issues.
Encore CS6 installs with no library. The "functional content" install that is presented first on that page link is step one. It installs an Encore library and styles (and some other content for Premiere), but that library consists of only a few templates, and not the full library with buttons, etc.
The library content with the buttons is in the section lower on that page which says "Additional Solution: Install the Resource Central library content."
The same files with the buttons can also be located from this link:
The process involves a "double extraction" of compressed files - the downloaded file is a .zip; when you extract it, you have another compressed file, a .7z. Just follow the instructions at the link.
If this doesn' twork for you, let us know.