MacHighway wants to find "index.php" at the end of my domain name -- but, the site i just created with C5 is found at: "domain name/builder".?? can anyone tell me how to change this?

Here is what MacHighway says:

If you see the MacHighway "Future home of..." welcome page....

...it means that the first page of your site isn't named index.htm, index.html, index.shtml or index.php, or you have uploaded your site to the wrong folder on the server. To remedy this, reload your pages and make sure they are placed directly inside the public_html directory.

since i didn't upload this file why would i have to move everything created with C5?
and HOW?