URL Installation Question?

[محروم.كوم]

When I placed the URL http://www.example.com/forums/install/install.php I didn't get the installation screen?

When I placed the URL http://example.com/forums/install/install.php I did get the installation screen?

I would like the site to run with the "www." in the URL. I just created the domain name about half an hour ago along with the new license. Any ideas? I don't recall running into this with other forums I created. __DEFINE_LIKE_SHARE__