It has been a while since I set mine up, but I remember that you do have to install the HD Homerun drivers on each machine. I installed the all the HD homerun software, so that I could verify that it was working before moving to Media Center. Once that is done, you need to set up the program guide on the server. If the clients are set to share the library with the server, they will get the guide from the server and you should be all set.
Alex