Hi,
> I open it from my html editor (dreamweaver) file >preview in browser .
You put your file in a folder itself located in wamp(64)\www\, for example wamp(64)\www\mysite\myfile.php
And you launch your file by typing in the address bar of the browser: 'http://localhost/mysite/myfile.php'
But, the solution is to use VirtualHost for your local sites, as with all hosting providers.
See
The need for Virtual Host---------------------------------------------------------------
Documentation Apache -
Documentation PHP -
Documentation MySQL -
Wampserver install files & addons