how to change Host for vanilla?

I installed vanilla in one hosting, and it runs well, and then I downloaded all the file,and uploaded into any other hosting, and also the database,but it tells me the following error when i run it

Fatal error: require_once() [function.require]: Failed opening required '/home/public_html/applications/controllers/class.controller.php' (include_path='.:/usr/lib/php:/usr/local/lib/php') in /home/public_html/library/core/class.dispatcher.php on line 531

so can you help me? thanks