Index: includes/install.core.inc
===================================================================
RCS file: /Users/wright/drupal/local_repo/drupal/includes/install.core.inc,v
retrieving revision 1.37
diff -u -p -r1.37 install.core.inc
--- includes/install.core.inc	4 Oct 2010 18:00:45 -0000	1.37
+++ includes/install.core.inc	7 Oct 2010 00:57:00 -0000
@@ -1755,7 +1755,7 @@ function _install_configure_form($form, 
     '#collapsible' => FALSE,
   );
 
-  $countries = country_get_list();
+  $countries = array_merge(array('' => t('No default country')), country_get_list());
   $form['server_settings']['site_default_country'] = array(
     '#type' => 'select',
     '#title' => t('Default country'),