The vBulletin 4 application comes with two main scripts: Forum and CMS. You can switch between them by editing the index.php file. If you want your visitors to open the CMS part by default, uncomment (remove the // string) the following line:

require('content.php');

Otherwise, if you want the visitors to load directly the Forum part, uncomment the following line:

require('forum.php');

Only one of the above lines can be uncommented. Put the // string in front of the other.