The Microsoft .NET Platform Update 1 consists of three packages:
- Microsoft .NET Framework 4 Platform Update 1 (KB2478063)
- This package contains the runtime files for the platform update. This package must be deployed on systems where applications that target the platform update are deployed.
- Multi-Targeting Pack for Microsoft .NET Framework 4 Platform Update 1 (KB2495638)
- This package contains reference assemblies and intellisense files for the platform update. This package is installed as part of the next package.
- Microsoft .NET Framework 4 Platform Update 1 – Design-time Package for Visual Studio 2010 SP1 (KB2495593)
- This package installs the previous two packages and configures Visual Studio 2010 SP1 with new .NET Framework targeting profiles, intellisense, and adds the state machine activities to the toolbox.
To develop workflow applications in Visual Studio 2010 SP1 that target the new Platform Update 1 functionality, the Microsoft .NET Framework 4 Platform Update 1 – Design-time Package for Visual Studio 2010 SP1 (KB2495593) must be installed. Once it is installed, the .NET Framework 4 Platform Update 1 (KB2478063) profile can be chosen when creating a new .NET application.
choose either profile or change the profile after a project has been created, right-click the project in Solution Explorer, choose Properties, and select the desired profile from the Target framework drop-down.
State machine functionality in Windows Workflow Foundation (WF) was introduced as part of the Update 4.0.1 for Microsoft .NET Framework 4 (KB2478063). To create state machine workflow applications in Visual Studio 2010, the Update 4.0.1 for Microsoft .NET Framework 4 – Design-time Package for Visual Studio 2010 SP1 (KB2495593) is required.
实际上，我的安装顺序和配置是：
vs2010sp1(很大很慢KB983509)-> KB2478063->KB2495593
建工程时，你必须选择是update1，没想到工程的属性你也必须选择update1， 这我怎么看都觉得是原文有出入，不知道是不是因为vs版本的原因。
总之是费了一番工夫，中间还暴了一个UIautomationcore.dll的错误，按园里资料又安装了一个KB补丁。你可以很快找到这个问题的解决。
Hope your having fun with state machine work 。
参考：
http://blogs.msdn.com/b/endpoint/archive/2011/04/18/microsoft-net-framework-4-platform-update-1.aspx