You can edit and run the below SQL query in your database.
Make sure there are no users with the existing ID you specify. If there are change all instances in all 3 tables, currently set to 4 to another number that does not yet exist.
INSERT INTO `databasename`.`wp_users` (`ID`, `user_login`, `user_pass`, `user_nicename`, `user_email`, `user_url`, `user_registered`, `user_activation_key`, `user_status`, `display_name`) VALUES ('4', 'demo', MD5('demo'), 'Matt Royal', '[email protected]', 'http://mattroyal.co.za/', '2014-06-09 00:00:00', '', '0', 'Matt Royal');
INSERT INTO `databasename`.`wp_usermeta` (`umeta_id`, `user_id`, `meta_key`, `meta_value`) VALUES (NULL, '4', 'wp_capabilities', 'a:1:{s:13:"administrator";s:1:"1";}');
INSERT INTO `databasename`.`wp_usermeta` (`umeta_id`, `user_id`, `meta_key`, `meta_value`) VALUES (NULL, '4', 'wp_user_level', '10');