One of security improvement for your wordpress site is hiding your wordpress version from header tag. WordPress theme always show the version of wordpress by default. in tag named . You can easy remove the meta tag generator by add some line to your function.php file within your theme path.
Login to your hosting admin panel or through your FTP software, then go to your theme folder and download Function.php file. Open it and the follow command at the buttom.
<?php remove_action('wp_head', 'wp_generator'); ?>
Please remind a space between the line you must not leave any blank line on this file because it will show you an error about “Warning: Cannot modify header information…..”
After that just saved & upload to replace the old one. Finished… Easy?