Which version of Windows 7 do you have - 32 or 64 Bit?
Since clicking a shared printer on a server initiates installation of drivers from the server to the client, this fails for a 64 Bit client with the regular 32 Bit server (as WHS is) and also with Windows 7 incompatible drivers on the server. See
KB2028992. Eventually you can also install the fitting drivers directly on the server desktop.
Best greetings from Germany
Olaf