I am able to access my new DNN install through http://localhost:27265/ but not through http://www.dnndev.me/

I have watched the four of Chris YouTube videos on DNN setup multiple times and followed every instruction as specified. Below is the screenshot of some of the efforts that I have made. 

I installed DNN from the gallery and manually without success. The only was I can access the install is to run WebMatrix and then run the site. All I want is to use Chris template to start learning module development. I cannot install template because it cannot access dnndev.me/desktopmodules.

I can use any help and I have read most dnndev.me forum posts and have spend two days in two machines trying to get this right.

Thanks @ James Brown. Your guess is probably right. I am doing everything I possibly can to address this issue. I have now troubleshoot this issue to the following error:

HTTP Error 500.21 - Internal Server Error - Handler "ExtensionlessUrl-Integrated-4.0" has a bad module "ManagedPipelineHandler" in its module list

I have uninstalled and re-installed .Net and ASP.Net on this machine.

And regarding the port number, when you create a website with WebMatrix or the web installer, it creates its own bindings in C:\Users\%USERNAME%\Documents\IISExpress\config\applicationhost.config and for me this is the record that Web Installer inserted and I am not sure if there is any connection.

 <site name="dnndev.me" id="4">

                <application path="/" applicationPool="Clr4IntegratedAppPool">

                    <virtualDirectory path="/" physicalPath="C:\websites\dnndev.me" />

                </application>

                <bindings>

                    <binding protocol="http" bindingInformation="*:27265:localhost" />

                </bindings>

            </site>

Thanks James for your time, was a wild chase but finally fixed by running this  command C:\Windows\Microsoft.NET\Framework64\v4.0.30319\aspnet_regiis.exe -i

per this StackOverflow question