Fiddler does not by default work together with the ASP.NET development server, however you can easily fix this.
In Fiddler press Ctrl+R (Rules) and go to the “OnBeforeRequest” method, here you add a single line:
oSession.host = oSession.host.replace("mhanotebook","127.0.0.1");
The “mhanotebook” is the name of your computer. The problem is that Fiddler works as a proxy and change this settings in IE7 to forward request to fiddler. however IE7 does not forward calls if the url contains localhost.
After applying the above rule, you can now do a request like this: http://mhanotebook:50016/product and Fiddler will “kick in”, nice :-)