http://localhost/Symfony/web/config.php gives us:
1 .Install and enable a PHP accelerator like APC (highly recommended).
2. Install and enable the intl extension.
3. Set short_open_tag to off in php.ini*.
(1) install corresponding php_apc.dll, add extension=php_apc.dll to php.ini
(2) mod_intl.dll exist, enable it in php.ini, but you need to have to copy all icu*36.dll files from your-xampp-path\php to your-xampp-path\apache\bin
(3) bad default-xampp-php.ini, "short_open_tag" is set twice - once "off" and once "on" two lines later, comment the latter out
http://localhost/Symfony/web/config.php is still not satisfied:
1. Upgrade your intl extension with a newer ICU version (4+).
damn ... I'm just one minute away from deinstalling xampp and take full control