Editing the Presentation config.php File 
New in vBulletin 5 is the Presentation configuration file. It is always located in the forum root or / directory of your vBulletin package. In a newly unzipped package, this would be the upload folder.
When editing a config.php file, make sure there is no whitespace or extra lines either before the <?php. If there are any extra lines or space, you will see an 'Unable to add headers' error when accessing your forums.
Editing the presentation config.php file is one of the few times in vBulletin where you will be required to edit raw PHP code. The file is heavily commented in order to help you fill in the necessary information.

You are only required to edit a one of the settings in this file to create a working vBulletin configuration file. These settings are:
Variable Name
$config['baseurl']This is the URL of your vBulletin installation. Do not use a trailing slash.
The rest of the settings in this file will not need to be edited at this time. We will cover them in a documentation update coming soon.
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