If the user enters an address in the address bar is a dynamic page, IIS can not be processed because the C # code for dynamic pages only just met .Net Framework, IIS does not recognize itself. Then find a aspnet_isapi.dll IIS file extensions according to dynamic pages visited by the contents of the file in the dynamic page requested to the .Net Framework, both because if the installation can not find the file after reverse so We can not handle dynamic pages.
When IIS installed and then install .Net Framework, due to the detection system has been installed IIS, this will automatically register mapping in IIS, aspx and ashx processing such as processing extensions.
IIS dynamic pages can be processed to see in the handler mapping,
It should be properly installed iis, then install vs, or an error occurs, the solution is to open CMD with administrators execute% windir% \ Microsoft.NET \ Framework \ v4.0.30319 \ aspnet_regiis.exe -i