Installation Problem!! Totally Stuck!!

Okay so this is my first time installing WordPress on my new website and I just hit a major block. I am on Step 5: Run the Install Script. I put WordPress in my root directory and it says I should go to http://mysite.com/wp-admin/install.php. So I keep putting in http://pixel.sprinkles.me/wp-admin/install.php, but it keeps coming up as HTTP 404 Not Found. Can someone please help? I checked everything of mine and there shouldn’t be any problems!