iis7_save_url_rewrite_rules()

function iis7_save_url_rewrite_rules(){
	if ( is_multisite() )
		return;

	global $wp_rewrite;

	// Ensure get_home_path() is declared.
	require_once( ABSPATH . 'wp-admin/includes/file.php' );

	$home_path       = get_home_path();
	$web_config_file = $home_path . 'web.config';

	// Using win_is_writable() instead of is_writable() because of a bug in Windows PHP
	if ( iis7_supports_permalinks() && ( ( ! file_exists($web_config_file) && win_is_writable($home_path) && $wp_rewrite->using_mod_rewrite_permalinks() ) || win_is_writable($web_config_file) ) ) {
		$rule = $wp_rewrite->iis7_url_rewrite_rules(false, '', '');
		if ( ! empty($rule) ) {
			return iis7_add_rewrite_rule($web_config_file, $rule);
		} else {
			return iis7_delete_rewrite_rule($web_config_file);
		}
	}
	return false;
}