Differences between the way WAMP and XAMPP handle vhosts?

I'm switching from WAMP to XAMPP and XAMPP has broken my vhosts. It won't allow access to them.

"You don't have permission to access the requested directory. There is either no index document or the direct开发者_如何学Goory is read-protected."

The Apache error log says:

"[error] [client 127.0.0.1] client denied by server configuration"

What does WAMP set that XAMPP doesn't in order to make the vhosts work?

Some possible reasons:

• You are missing a <Directory> container to allow access to that file tree:

  <Directory "C:/Foo/Bar/">
      Order allow,deny
      Allow from all
  </Directory>
  

• You are using PHP but index.php is not defined as directory index:

  DirectoryIndex index.php
  

• The directory is read-protected