CodeIgniter: 404 Page Not Found on Live Server
You are using MVC with OOPS Concept. So there are some certain rules.
1) Your class name (ie: controller name) should be start with capital Letter.
e.g.: your controller name is 'icecream'. that should be 'Icecream'
In localhost it might not be compulsory, but in server it will check all these rules, else it can't detect the right class name.
Changing the first letter to uppercase on the file's name and class name works.
file: controllers/Login.php
class: class Login extends CI_Controller { ... }
The file name, as the class name, should starts with capital letter. This rule applys to models too.