Installing PEAR on Windows 7 using phar

I'm trying to install PEAR for use with Wamp 2.1. The package does not come with any pear installation. I have read that you need to use http://pear.php.net/go-pear.phar to install PEAR for PHP 5.3 as the old go-pear.bat is now obsolete? The instructions are to run the following command to install PEAR; php -d phar.require_hash=0 PEAR/go-pear.phar However, this is resulting in the following error;