Configure IISExpress

I tried to open a sample application that used IISExpress and received this error:

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Microsoft Visual Studio
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Configuring Web http://localhost:57370/ for ASP.NET 4.0 failed. You must manually configure this site for ASP.NET 4.0 in order for the site to run correctly. Could not find the server 'http://localhost:57370/' on the local machine. Creating a virtual directory is only supported on the local IIS server.

But as I use IIS (proper) on my development machine as well it wouldn't auto configure it. The answer was to configure it manually via:
%userprofile%\documents\IISExpress\config\applicationhost.config

<configuration>
<system.applicationHost>
<sites>
            <site name="[site name]" id="2">
                <application path="/" applicationPool="Clr4IntegratedAppPool">
                    <virtualDirectory path="/" physicalPath="[path to site]" />
                </application>
                <bindings>
                    <binding protocol="http" bindingInformation="*:57370:localhost" />
                </bindings>
            </site>
</sites>
</system.applicationHost>
</configuration>