Remove Default Widgets in WordPress

Put this in functions.php file to remove all the default widgets.

<?php
function remove_default_widgets() {
     unregister_widget('WP_Widget_Pages');
     unregister_widget('WP_Widget_Calendar');
     unregister_widget('WP_Widget_Archives');
     unregister_widget('WP_Widget_Links');
     unregister_widget('WP_Widget_Meta');
     unregister_widget('WP_Widget_Search');
     unregister_widget('WP_Widget_Text');
     unregister_widget('WP_Widget_Categories');
     unregister_widget('WP_Widget_Recent_Posts');
     unregister_widget('WP_Widget_Recent_Comments');
     unregister_widget('WP_Widget_RSS');
     unregister_widget('WP_Widget_Tag_Cloud');
     unregister_widget('WP_Nav_Menu_Widget');
}

add_action( 'widgets_init', 'remove_default_widgets' );
?>