The requested URL /about was not found on this server

If all above point not work. Then try this one. I tried it. It’s working for me.

1. Go /etc/httpd/conf/httpd.conf.
2. Change the AllowOverride None to AllowOverride All.
3. Restart the apache server.

UPDATE 2017

For new versions of apache the file is called apache2.conf

So to access the file, type sudo nano /etc/apache2/apache2.conf and change the correspondent line inside block <Directory /var/www >