My Question: If we don't change the property to .Net Framework 4, the scale out assemblies cant be used in Windows Presentation Foundation project. Please send me the reason that why it can't be accessible by setting the property .Net Framework 4 Client Profile?
The ScaleOut assemblies are designed to be used on server deployments and require a full version of the .NET Framework. You can compile WPF projects referencing .NET Framework 4. There is not a big difference in size between these two deployment options of .NET Framework 4. In fact, starting with the .NET Framework 4.5, the Client Profile option is no longer available (you can read more about that here: http://msdn.microsoft.com/en-us/library/vstudio/cc656912(v=vs.100).aspx).