localhost subsites configuration
You need to create symbolic links in order that your drupal7_sub1 and drupal7_sub2 directories works. Those symlinks needs to target your drupal7_main directory.

To create a symlink, open a commandline tool and execute following commands (if your on a Windows machine). You need to put the correct paths depending your localhost configuration.

First go to root directory of your localhost

cd C:/wampp/htdocs/


Create symlink for each subwebsite (drupal7_sub1, drupal7_sub2)

mklink /D drupal7_sub1 C:/wampp/htdocs/drupal7_main
mklink /D drupal7_sub2 C:/wampp/htdocs/drupal7_main


Executing this will already give you a result when visiting localhost/drupal7_sub1. If everything went well, you should see your localhost/drupal7_main website.

Because your working with a localhost URL (and not real domain name, can be a development URL only existing on local, i.e. dev.yourproject.com), you need to slightly adapt your folder structure in order that each subwebsite uses its own settings.php and file folder for the files (uploads, css, ctools, js).

You need to prefix your subfolders under drupal7_main/sites/ with localhost.

drupal7_main/sites/drupal7_sub1 --&gt; drupal7_main/sites/localhost.drupal7_sub1
drupal7_main/sites/drupal7_sub2 --&gt; drupal7_main/sites/localhost.drupal7_sub2