make wordpress folder as default site

need to make a wordpress folder to be the default loading page when visitors access my main site and index page. right now the site uses the old design and pages which i still want to leave on the server.

i am trying to make wordpress folder which has already been installed to be the default pages access by all of my visitors.

site is hosted on a windows godaddy server. so .htaccess is not an optio.

please help thanks