wordpress dosyaların içinde wp-includes/widgets.php dosyasını açıp bu kodu bul;

function wp_widget_recent_entries($args) {
	if ( '%BEG_OF_TITLE%' != $args['before_title'] ) {
		if ( $output = wp_cache_get('widget_recent_entries', 'widget') )
			return print($output);
		ob_start();
	}

	extract($args);
	$options = get_option('widget_recent_entries');
	$title = empty($options['title']) ? __('Recent Posts') : apply_filters('widget_title', $options['title']);
	if ( !$number = (int) $options['number'] )
		$number = 10;
	else if ( $number < 1 )
		$number = 1;
	else if ( $number > 15 )
		$number = 15;

	$r = new WP_Query(array('showposts' => $number, 'what_to_show' => 'posts', 'nopaging' => 0, 'post_status' => 'publish', 'caller_get_posts' => 1));
	if ($r->have_posts()) :
?>

bu kod ile değiştir, artık 25 adet olacak üst sınır;

function wp_widget_recent_entries($args) {
	if ( '%BEG_OF_TITLE%' != $args['before_title'] ) {
		if ( $output = wp_cache_get('widget_recent_entries', 'widget') )
			return print($output);
		ob_start();
	}

	extract($args);
	$options = get_option('widget_recent_entries');
	$title = empty($options['title']) ? __('Recent Posts') : apply_filters('widget_title', $options['title']);
	if ( !$number = (int) $options['number'] )
		$number = 10;
	else if ( $number < 1 )
		$number = 1;
	else if ( $number > 25 )
		$number = 25;

	$r = new WP_Query(array('showposts' => $number, 'what_to_show' => 'posts', 'nopaging' => 0, 'post_status' => 'publish', 'caller_get_posts' => 1));
	if ($r->have_posts()) :
?>

sonra panelden ayarlarken parantez içinde hala en fazla 15 yazar, onu değiştirmek için yine aynı dosyada bunu bul;

			<p><label for="recent-entries-title"><?php _e('Title:'); ?> <input class="widefat" id="recent-entries-title" name="recent-entries-title" type="text" value="<?php echo $title; ?>" /></label></p>
			<p>
				<label for="recent-entries-number"><?php _e('Number of posts to show:'); ?> <input style="width: 25px; text-align: center;" id="recent-entries-number" name="recent-entries-number" type="text" value="<?php echo $number; ?>" /></label>
				<br />
				<small><?php _e('(at most 15)'); ?></small>
			</p>
			<input type="hidden" id="recent-entries-submit" name="recent-entries-submit" value="1" />

bununla değiştir;

			<p><label for="recent-entries-title"><?php _e('Title:'); ?> <input class="widefat" id="recent-entries-title" name="recent-entries-title" type="text" value="<?php echo $title; ?>" /></label></p>
			<p>
				<label for="recent-entries-number"><?php _e('Number of posts to show:'); ?> <input style="width: 25px; text-align: center;" id="recent-entries-number" name="recent-entries-number" type="text" value="<?php echo $number; ?>" /></label>
				<br />
				<small><?php _e('(en fazla 25)'); ?></small>
			</p>
			<input type="hidden" id="recent-entries-submit" name="recent-entries-submit" value="1" />

artık olmuş olması gerekiyor. bir bak dene bakalım.