 <p>Skype was hogging port 80</p> <p>I came to this conclusion from using this on the command line:</p> <p>netstat -ano</p> <p>Then finding the PID against port 80 in Task Manager</p> <p>Then quitting skype and seeing the issue go away. </p> <p>I resolved the conflict by changing Skype settings to leave port 80 alone. This also explains why the 404 was not an IIS styled 404 page and why there was nothing in the IIS logs - just a question mark against the default website icon.</p>