Using a virtual host result in internal error
Looks like the .htaccess file included with Craft is not being read or you didn't rename it (should be .htaccess with the period at the beginning). 

That's why /index.php/admin is working but /admin/ is not.

One other possibility is Apache is setup to ignore .htaccess files. If that's the case, add this to your httpd-vhosts.conf file.

&lt;Directory "C:\wamp\www\y-lynx"&gt;
    AllowOverride All
&lt;/Directory&gt;


(If you already have a &lt;Directory "C:\wamp\www\y-lynx"&gt; block, just add in AllowOverride All somewhere inside.)