I am on UBUNTU 13.04 . I had installed "Example For Developer" from https://drupal.org/project/examples
and now that didn't wanted it, i deleted the example folder from /sites/all/modules and after i deleted folder
(the folder had a lock icon , i deleted using sudo command ) the site is not running now .. i tried to put the
folder again but it doesnot work . please help me to recover my site.