I was having trouble opening a web services solution. I kept getting the following error:
---------------------------Microsoft Visual Studio---------------------------The application for project 'http://localhost/MyVirtualWebApp' is not installed.
Make sure the application for the project type () is installed.---------------------------OK Help ---------------------------
Took me a while to figure out what was going on, but I finally found out why I'm getting this error. It was because I didn't have the 'Visual Web Developer' component installed (option to install this is in the Visual Studio setup process). Installing that did the trick.
A similar error I believe happens for all other solution types. If you get this, check that you have the appropriate Visual Studio components installed...