A few things to help debug:
When you get the blank screen, is there anything "interesting" if you use your browser's "view source" feature?
Is there anything in your php error log? (You may need to do some poking around and/or Googling to find out where wampstack puts it.)
Alternatively, changing your php.ini file to turn on "display_errors" will output those error messages right to the browser. Or, if it's not a plain old syntax error somewhere in the code, you can stick this at the top of the file being called:
<?php
ini_set('display_errors', true); // set to false in production
error_reporting(E_ALL);
My initial suspicion is that something in that installation process specified an absolute file path that now is failing when you moved the files...but that's purely a guess for now.