Steps to remove index.php from requested url in magento.
1. Goto root/var folder and open .htaccess file and remove existing lins and repalce the following lins,
RewriteEngine On
RewriteBase /
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)$ index.php/$1 [L]
2. Goto System->Configuration->Web->Search Engines Optimization, change to "Yes".
3. Goto System->Cache Management->Clear all cahces
