Have you ever opened a web project and had it say Unable open project “yourprojectName“. The file path “…\yourproject\“ does not correspond to the URL ‘http://localhost:/youprojectName“. The two need to map to the same server location.  HTTP Error 404: Not Found.

Well the problem is that you don’t have a virtual directory defined that matches what VS.NET is expecting.  To find out the name of the project that VS.NET is expecting there is a file called projectname.webinfo in the same directory as the files.  An example of this is.

<VisualStudioUNCWeb>
    <Web URLPath = “http://localhost/Payments/Payments.csproj” />
</VisualStudioUNCWeb>

As you can see this file contains the URLPath to the Virtual Directory that the project is expecting.  All you need to do is to create a Virtual Directory that matches the name specified or if you have already created a virtual directory just edit the file and make them the same.