Could not load type 'Microsoft.Expression.DesignModel

Error    1    Could not load type 'Microsoft.Expression.DesignModel.Core.ISharedInstanceBuilder' from assembly 'Microsoft.Expression.DesignModel, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a'.    C:\Users\Owner\documents\visual studio 2010\Projects\WpfApplication1\WpfApplication1\Window1.xaml    1    1    WpfApplication1


I am using Microsoft Visual c# 2010 express edition. Whenever I am trying to see design window it always display above error.How to solve this problem?

Thanks in advance.
Chirag Patel