ZINKKK adlı üyeden alıntı: mesajı görüntüle
aynen hocam.
.htaccess dosyasının içerisine şunları yapıştırın. Alıntıladığınız kişi sorunu çözdü.

<ifModule mod_rewrite.c>
RewriteEngine On
# Because it located in http://localhost/codeigniter, so rewriteBase will have same value
RewriteBase /codeigniter/

#Removes access to the system folder by users.
#Additionally this will allow you to create a System.php controller,
#previously this would not have been possible.
#’system’ can be replaced if you have renamed your system folder.
RewriteCond %{REQUEST_URI} ^system.*
RewriteRule ^(.*)$ /index.php?/$1 [L]

#When your application folder isn’t in the system folder
#This snippet prevents user access to the application folder
#Submitted by: Fabdrol
#Rename ‘application’ to your applications folder name.
RewriteCond %{REQUEST_URI} ^application.*
RewriteRule ^(.*)$ /index.php?/$1 [L]

#Checks to see if the user is attempting to access a valid file,
#such as an image or css document, if this isn’t true it sends the
#request to index.php
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)$ index.php?/$1 [L]
</ifModule>

<ifModule !mod_rewrite.c>
ErrorDocument 404 /index.php
</ifModule>