Links for Installing State Machine Workflow 4.0 for Visual Studio 2010.

If you do not have Microsoft Visual Studio 2010 Service Pack 1 installed, please install

• Microsoft Visual Studio 2010 Service Pack 1

And then install Microsoft .NET Framework 4 Platform Update 1

• Microsoft .NET Framework 4 Platform Update 1 – Design-time Update for Visual Studio 2010 SP1 (KB2495593)