If you are using Microsoft Internet Explorer running under Windows, use "Windows Update" to install the "Simplified Chinese" language pack. (Depending on which version of Windows you are running, "Windows Update" might be under the "Tools" menu item in the browser, or it might be under the main "Start" menu of Windows itself.) After doing this, go back to the "Hanzi Display" page and verify that the two boxes now look alike.

If you are using any other Browser or Operating System, you will have to refer to your own system's documentation for multi-lingual fonts. We intend to add more helpful documentation here someday, but there are a lot of combinations and we simply haven't had the resources to do that yet.