http://static.phalconphp.com/files/phalcon_x86_VC9_php5.3.9_1.3.4_nts.zip

Secondly, you should abstract this zipped file.

To add the extension, got to the extension directory, <install_path>\ZendServer\phpext, and add the .dll file there.

Go to your php.ini file and add the following line: extension=<extension_name>.dll.

At default, php.ini is in this path <install_path>/ZendServer/etc/php.ini.

After all, you can use phpinfo() to check it out whether phalcon is work in your server.

If you can see phalcon, then it works and starting your coding.

Thanks a lot.

PHP Official Function - How to install extension in Zend Server,  the link is here.

http://files.zend.com/help/Zend-Server-6/content/adding_extensions.htm