activation link sent to email not working after registration !

[eluser]Unknown[/eluser]
hi !

im new to code igniter and this is my first attempt working with it ! , my problem is with link sent to email after i tried to register , i did recieve verification link but when i open it it shows :

Code:

No input file specified.

link :

Code:

http://domain.name/auth/activate_account/4/62400846a5fc100c0e0086d24e7ee66d2fbbd9c1

any help ?

[eluser]Unknown[/eluser]
solved it using :

Code:

http://domain.name/index.php/auth/activate_account/4/62400846a5fc100c0e0086d24e7ee66d2fbbd9c1

as a link .. how to remove index.php ? cuz it caused more problems !

[eluser]Storyteller[/eluser]
http://ellislab.com/codeigniter/user-gui.../urls.html

The second section there describes it.