Deny access to a directory with web.config

From: Matt (none_at_none.com)
Date: 04/26/05 

Date: Tue, 26 Apr 2005 21:56:56 +0200

Hello,
I'm working on a portal based on IBuySpy, where the main page is
desktopdefault.aspx and all content is stored in
www.domain.com/content/html/nnn
or
www.domain.com/content/images/nnn
and injected in the desktopdefault.aspx page.

How can I prevent users doing www.domain.com/content/images/test.jpg
and getting the image (or the html file, or whatever inside the
content directory?)
It doesn't matter if the user is authenticated or not, I just want
obly the webapplication to be able to load and display the files
inside the /content directory.

Can I do this just manipulating the web.config, without changing
directory permissions on the webserver?

Thanks!