Q:

'Unable to open WampServer's config file, please change path in index.php file' not opening localhost in browser

Recently I've been using WAMP server for my project.  But due to some reason I need to switch to XAAMP server, so I uninstalled WAMP server and installed XAAMP server.  
But when I open localhost in my browser it says:

Unable to open WampServer's config file, please change path in index.php file

What might be the problem? 

A:

I had the same problem - check your www folder - delete index.php
Edit: The index.php is an unnecessary default home page for Wamp server which will cause the error when running from an XAAMP htdocs folder.  In other words, your localhost is working, you've just got an index.php file from the old WAMP install. 

A:

you can edit your index.php and if you move it from one place to another, just change like this:
$wampConfFile = 'c:/wamp/wampmanager.conf';
$aliasDir = 'c:/wamp/alias/';
$vhostsDir = 'c:/wamp/vhosts/';

