If you want to deregister CF7's scripts and styles, you should consider this method :

In your wp-config.php:

define('WPCF7_LOAD_JS', false);




define('WPCF7_LOAD_CSS', false);

And if you want to register them again for a specific page, then in your function.php write something like that:

if ( is_single('contact') ) {




  wp_register_style( 'contact-form-7', 100 );




  wp_register_script( 'contact-form-7', 100 );




}

Or see complete explanations here :

Hope it will help!