need help to activate WP-Stats-Dashboard

hi, im new with www.ads-software.com. for my site right now i try to install WP-Stats-Dashboard just like on wordpress.com. after installing plugin and enter WordPress.com API key, my plugin still didnt started. it said, you must have CURL extension enabled in your php configuration. my question is how to do that:)
please help me to activate my plugin. I would be very grateful for your assistance