Cannot find JavaScriptSerializer in .Net 4.0

1. Right click References and do Add Reference, then from Assemblies->Framework select System.Web.Extensions.
2. Now you should be able to add the following to your class file:

    using System.Web.Script.Serialization;

Check if you included the .net 4 version of System.Web.Extensions - there's a 3.5 version as well, but I don't think that one works.

These steps work for me:

1. Create a new console application
2. Change the target to .net 4 instead of Client Profile
3. Add a reference to System.Web.Extensions (4.0)
4. Have access to JavaScriptSerializer in Program.cs now :-)

From the first search result on google:

http://msdn.microsoft.com/en-us/library/system.web.script.serialization.javascriptserializer.aspx

JavaScriptSerializer Class

Provides serialization and deserialization functionality for AJAX-enabled applications.

Inheritance Hierarchy

System.Object

System.Web.Script.Serialization.JavaScriptSerializer

Namespace: System.Web.Script.Serialization

Assembly: System.Web.Extensions (in System.Web.Extensions.dll)

So, include System.Web.Extensions.dll as a reference.