VS2010 reference dll is missing from the list

I'm trying to add System.Web.Extensions.dll to my C# console application so I can parse JSON. I'm using VS2010.

W开发者_如何学编程hen I right click -> Add reference though it does not list the dll. However when I search for the file on my computer it does exist.

Please advise on the proper way to add this dll.

Right click on your project and go to properties.

In the Target framework drop down ensure that you have ".NET Framework 4" selected and not ".NET Framework 4 Client Profile".

When you have Client Profile selected it will filter out the server side dlls like System.Web and System.Web.Extensions