Make sure you have 'HTTP_IMAGE' in your config.php, or you will have 'HTTP_IMAGE' error
define('HTTP_IMAGE', 'yourwebsiteaddress/image/');

OCMod:

Go to 'Extension Installer' -> Upload File 'Admin_Customer_Country_OCMod.xml'

VQMod: Make sure you have VQMod installed.

Copy 'Admin_Customer_Country_VQMod.xml' to /vqmod/xml/ . No file need to edit or replaced.

It may not work with custom template.

Find more extensions from http://www.opencart.com/index.php?route=extension/extension&filter_username=cathyshea