Problem in installing Entity Framework in VS 2010.

Question

Using nuget package manager,I install Entity manager (Version:6.3.0) using these steps:

 

Open visual studio > Tools > Library Package Manager > Manage NuGet Packages for Solution

 

 

 

But at the end of installation.It gives the error message

 

 

Please Help me guys to resolve this problem.As I have to practice

Data access in mvc using entity framework,so I have install Entity Framework.Iam using MVC 4 and .NET 4.0 Version

 

Thank you in advance.