After installing the content on your computer, open Architectural Desktop and then open the Content Browser.
Step 1 - Click on "Create a Catalog"
Step 2 - Click on the "Browse" button and search for the folder on your C drive:
for Marvin - c:\Marvin_Windows_and_Doors_ADT\Marvin_Windows
for Integrity - c:\Integrity_Windows
Step 3 - Open the .ATC file