It means IIS 6 is either not configured correctly during installation or Asp.net is not registered with IIS. So you need to remove IIS 6 in add remove Windows component and add it again this time click on details and add all the features needed to run Asp.net. Then go to the location below in your C drive and run aspnet_regiis. The reason IIS 6 comes locked down to render only static html.
C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727