Enable mod_rewrite Ubuntu 14.04

 sudo a2enmod rewrite

 In 14.04, the name of the default configuration file is changed to 000-default.conf :

sudo gedit /etc/apache2/sites-available/000-default.conf 

add the following to the end of the file :

<Directory "/var/www/html"> AllowOverride All </Directory> 

sudo service apache2 restart

http://askubuntu.com/questions/48362/how-to-enable-mod-rewrite-in-apache