Woah - you cant delete that line of code from your web.confg.

But by setting your initial website up using a port number - there is a setting that gets forced to true in your web.config.

<!-- set UsePortNumber to true to preserve the port number if you're using a port number other than 80 (the standard)
-->
    <add key="UsePortNumber" value="true" />

In a normal dnn install that particular line is commented out - but im guessing that its not commented out in yours.

<!-- set UsePortNumber to true to preserve the port number if you're using a port number other than 80 (the standard)
    <add key="UsePortNumber" value="true" />
-->

But having said this - I'm not aware that it would necessarily cause this sort of problem on its own.

If you look in your portals settings - portal aliases - you will most likely find that your portal alias explicitly references the 1960 port.
In which case you will need to add a new portal alias for http://localhost/vnguest/ to your aliases before dnn will recognise that it exists.

Westa