Cannot access to localhost xampp index php

Question

When I type localhost in my browser "Google Chrome" it sends me to "http://localhost/dashboard/" and then if I change the URL to "//localhost/xampp/index.php", it returns: 

Object not found! The requested URL was not found on this server. If you entered the URL manually please check your spelling and try again.

If you think this is a server error, please contact the webmaster.

Error 404

localhost Apache/2.4.16 (Win32) OpenSSL/1.0.1p PHP/5.6.11

Can someone help me with this error?