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.

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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