[Michael Morris]

You seem to be confusing internal and external paths. On a linux machine the complete internal path will start with a /. On Windows it will start with a drive letter, such as c:\

You must provide the internal path from the root of the drive to get the script to work. For example

/var/www/sites/pinkowitz.org/subdomains/www/ for Joomla and
/var/www/sites/pinkowitz.org/subdomains/forum/ for vbulletin, and so on.

One way to discover the path is to create a new php file in your forum with this code

PHP Code:

<?php echo dirname(__FILE__); ?>

Visit the file in your browser and copy whatever appears to the vJoomla installer.