ASP.NET What causes: It is an error to use a section registered as allowDefinition=’MachineToApplication’ beyond application…?

I have an ASP.NET web site. I keep getting the error below in VS 2008. The site works fine from a browser. I have made every folder using IIS manager an ASP.NET app. Why does it keep complaining? The site’s folder is below a parent folder.
I am not familiar with web site apps instead of web application app. Where are the options to use IIS or the internal web server like WAP has?