Remove dashboard widgets

add_action('wp_dashboard_setup', 'rf_remove_dashboard_widgets' );
function rf_remove_dashboard_widgets() {
  // this function removes the standard dashboard widgets for all users, including the main admin
  global $wp_meta_boxes;
  unset($wp_meta_boxes['dashboard']['side']['core']['dashboard_quick_press']);
  unset($wp_meta_boxes['dashboard']['normal']['core']['dashboard_incoming_links']);
  unset($wp_meta_boxes['dashboard']['normal']['core']['dashboard_right_now']);
  unset($wp_meta_boxes['dashboard']['normal']['core']['dashboard_plugins']);
  unset($wp_meta_boxes['dashboard']['normal']['core']['dashboard_recent_drafts']);
  unset($wp_meta_boxes['dashboard']['normal']['core']['dashboard_recent_comments']);
  unset($wp_meta_boxes['dashboard']['normal']['core']['dashboard_activity']);
  unset($wp_meta_boxes['dashboard']['side']['core']['dashboard_primary']);
  unset($wp_meta_boxes['dashboard']['side']['core']['dashboard_secondary']);
  remove_action( 'welcome_panel', 'wp_welcome_panel' );
  // the commented code below will display the full array so that you can see what other things should need to be removed
  /* 
    echo '<pre>';
    print_r($wp_meta_boxes);
    echo '</pre>';
  */
}