Research on the web turned out several methods of troubleshooting this particular issue.
I will give you several methods to try and hope they help you out:
The first one includes watching a youtube video that discusses this particular error. It's better if you can actually see the resolution to your issue, at least in my opinion. Here's the video
Check your subwebs. They could be pointing to a different path or a path that you previously were working on but changed it recently. Update each subwebs' applications Basic Settings to point to the correct path
Compile your project and select C:Inetpubwwwroot<projectname> as the repository for your deployable files. Make sure that the path of the application under IIS points to the new path
Set the web application's folder permissions so that the following are included: ASPNET and IIS_IUSRS and IUSR
Arthur It's first good to remind that the ASP is an acronym for Active Server Pages which is a language of .net which is developed by Microsoft and this language is similar to C and also it is majorly used in many programs for smooth execution.
Coming to Windows Application Form in ASP it is simple, and as it is drag and drop and no need to generate any code for that as automatically code will be generated.
The problem might be completely due to the incomplete installation of IIS successfully and also error you shown may also occur if the source is not available so the error may be with IIS or else the running script.
Coming to IIS which can be said as an Internet Information Server first check this whether the installation is successful or not by accessing the local host in any browser.