So you have Hostgator and you installed osCommerce. Then you tried to use your FTP Client to change the permissions to 444 with no luck? Keep getting this message?
Warning: I am able to write to the configuration file: /home/*public_html/includes/configure.php. This is a potential security risk – please set the right user permissions on this file.
Use cpanel’s filemanager and change includes/configure.php to 444 from there. For some reason Hostgator doesn’t allow you to change it from your FTP Client.