PHP Require_once error

I'm currently working on a register page for my site. I use "require_once" to find the config file.

On the register-exec.php page it has this line:

require_once('/zds/include/php/config/config.php');

In the config file, it contains my database information.

When I try to register a user, it shows this:

Warning: require_once(/zds/include/php/config/config.php): failed to open stream: No such file or directory in C:\xampp\htdocs\zds\register-exec.php on line 3
Fatal error: require_once(): Failed opening required '/zds/include/php/config/config.php' (include_path='.;C:\xampp\php\PEAR') in C:\xampp\htdocs\zds\register-exec.php on line 3

Any help? :/