Cannot get CI to work on localhost, but work on shared hositng

Hi guys

Need help. Just started with CI today. And I'm doing the static page tutorial to create the home and about page. I manage to get it work on a shared account on hostgator, but not on my localhost. Im getting 404 not found error. 

No database connectivity yet.

I have download the exact copy from Hostgator to my localhost, still have the same problem. I have change the base_url to localhost, still not working.

On the shared hosting, i can view the about page on http://mydomain.com/index.php/pages/view/about

On my local host, get 404 not found error http://localhost/index.php/pages/view/about


Is it how my web server is setup ? Im using nginx. Could this be the probelm ?