If you use Visual Studio to open a Web project that was developed for the .NET Framework 2.0, the .NET Framework 3.0, or the .NET Framework 3.5, Visual Studio can automatically perform all the changes to Web.config files that are required to be able to run using .NET Framework version 4. If the project is a local IIS project and you are using IIS 7.0, Visual Studio can also reassign the applicatio