Go to this link:
http://helpx.adobe.com/x-productkb/multi/library-functional-content-mi ssing.html
Step 1: Follow the instruction in the top part: "Solution: Install the CS6 Functional Content"
This will install the basic library. If you have CS5.5 installed, backup your Encore library there; it will be deleted by the install.
Step 2: Follow the instructions at the bottom of the link above: "Additional solution: Install the Resource Central library content"