page not found on install

Question

So i wanted to install Drupal on my local mac. I download drupal 7.12 put its content into my htdocs (i'm running MAMP) goto localhost got through all the steps and his save and it took me to "http://localhost/install.php?profile=standard&locale=en" where i get this message

then if i goto localhost i get this

I can't seem to figure out what went wrong Could some one point me in the right direction ?