The problem I see is that you already have a site installed in your main folder. If you want WordPress to become your main site, your existing site needs to be moved to a subfolder or even a subdomain. Then you can install WordPress.
If you want to install WP using One-Click you can rename your cwpnetwork.com folder to forum. Then create a new cwpnetwork.com folder and then use the One-Click install a custom WordPress into that domain. Once that's done, then move the "forum" folder into the cwpnetwork.com folder and edit your vbulletin settings to use the new subfolder.