This deals with the .NET Framework 3.0 Training Kit downloaded from the URL : http://wf.netfx3.com/blogs/news_and_announcements/archive/2007/02/13/net-framework-3-0-training-kit.aspx
If you get the following error while running http://localhost/DerivativesCalculator/Service.svc after setting up a virtual directory in IIS 7.0 -
"The type 'DerivativesCalculatorService.Calculator', provided as the Service attribute value in the ServiceHost directive could not be found. ",
Right click on the virtual directory and select "Convert to application". The thing is "You need both a Virtual Directory and an application root to get Indigo/ASP.NET to work."
More info here