add_action('wp_dashboard_setup', 'my_custom_dashboard_widgets');

function my_custom_dashboard_widgets() {
    global $wp_meta_boxes;

    // Right Now - Comments, Posts, Pages at a glance
    unset($wp_meta_boxes['dashboard']['normal']['core']['dashboard_right_now']);

    // Recent Comments
    unset($wp_meta_boxes['dashboard']['normal']['core']['dashboard_recent_comments']);

    // Incoming Links
    unset($wp_meta_boxes['dashboard']['normal']['core']['dashboard_incoming_links']);

    // Plugins - Popular, New and Recently updated Wordpress Plugins
    unset($wp_meta_boxes['dashboard']['normal']['core']['dashboard_plugins']);

    // WordPress Development Blog Feed
    unset($wp_meta_boxes['dashboard']['side']['core']['dashboard_primary']);

    // Other WordPress News Feed
    unset($wp_meta_boxes['dashboard']['side']['core']['dashboard_secondary']);

    // Quick Press Form
    unset($wp_meta_boxes['dashboard']['side']['core']['dashboard_quick_press']);

    // Recent Drafts List
    unset($wp_meta_boxes['dashboard']['side']['core']['dashboard_recent_drafts']);
}