Essential Downloads
To get started creating rich client applications with WPF and Windows Forms, you will need the following downloads.
These downloads are free. For more information on getting started with .NET Framework 4 go to the
get started page.

The Microsoft .NET Framework is a component of the Windows operating system. It provides the foundation for next-generation applications, including WPF and Windows Forms client applications.

Visual Studio 2010 Express Editions are FREE, easy-to-use, and easy-to-learn development tools for developing Windows-based applications. This download includes full language support (compiler, libraries) and the integrated development environment.

Microsoft Expression Blend is the professional design tool to create connected Windows experiences using WPF.