What are you saying about the english file?
After creating your logo you can adjust the height, width and logo name in includes/languages/ENGLISH/header.php

define('HEADER_ALT_TEXT', 'Powered by Zen Cart :: The Art of E-Commerce');
define('HEADER_LOGO_WIDTH', '192px');Change this to the width of your image
define('HEADER_LOGO_HEIGHT', '64px');Change this to the height of your image
define('HEADER_LOGO_IMAGE', 'logo.gif');