How to remove index.php in CodeIgniter?

for lighttpd:

enable mod_rewrite module and set this in you lighttpd.conf

server.document-root = "/var/www/ci/",
    url.rewrite-once = (
        "/(.*)\.(.*)" => "$0",
        "/(css|files|img|js|stats|user_guide)/" => "$0",
        "^/([^.]+)$" => "/index.php/$1"
    )

To avoid "index.php" from codeigniter url, follow the steps below.

1.Open config.php from system/application/config directory and replace

$config['index_page'] = “index.php” 
by 
$config['index_page'] = “”;

2.Create a “.htaccess” file in the root of CodeIgniter directory (where the system directory resides), open the file using your favorite text editor, write down the following script and save it:

RewriteEngine on
RewriteCond $1 !^(index\.php|resources|robots\.txt)
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)$ index.php/$1 [L,QSA]

3.In some case the default setting for uri_protocol does not work properly. To solve this problem just replace

$config['uri_protocol'] = “AUTO” 
by 
$config['uri_protocol'] = “REQUEST_URI”

from system/application/config/config.php

You just need to create .htaccess file in project folder and write:

RewriteEngine On

RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d

 # Rewrite all other URLs to index.php/URL 
  RewriteRule ^(.*)$ index.php?url=$1 [PT,L] 

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

   #And You don't need to define in base_url in config file:

      $config['base_url'] = '';// blank it.

I hope You Understand..