When you install joomla in test/sub folders/directory and after completion of test you want to move Joomla to the root folder of their hosting accounts.
We wanna change http://www.yourdomainname.com/test to http://www.yourdomainname.com
This change consists of the following steps:
Step-01: Move all of the files and folders from your Joomla folder to the new directory. Suppose from public_html/test to public_html
Step-02: Reconfigure your application. You should edit your configuration.php file and make the following changes in it:
Change: var $log_path = '/home/user/public_html/test/logs';
To: var $log_path = '/home/user/public_html/logs';
Change: var $tmp_path = '/home/user/public_html/test/tmp';
To: var $tmp_path = '/home/user/public_html/tmp';
Change: var $ftp_root = '/public_html/test';
To: var $ftp_root = '/public_html';
Change: var $live_site = 'http://www.yourdomain.com/test';
To: var $live_site = 'http://www.yourdomain.com';
Step-03: Remove the content of your cache folder (public_html/cache)
Now reload your website.