Application Not Installed
This dialog box appears with the error "The application for project <project> is not installed. Make sure the application for the project type (<projectextension>) is installed."
This dialog box appears because a product required to open the specified file was not found. It is common for this error to occur when attempting to open a project file that cannot be opened with the installed version of Visual Studio. For example, attempting to open a Visual C# project file with Visual Basic 2005 Express Edition will open this dialog box.
To workaround this error
Install the correct version of Visual Studio.