Looking at the error message, you might have a reference (a mention of) to System.Web.Extensions.dll in your web.config. Try and remove that line from web.config. If the machine does not have the 2.0 version of the System.Web.Extensions.dll that could be your issue. You may need to re-download/install the .NET 2.0 version of the Ajax extensions from here: http://www.microsoft.com/downloads/details.aspx?FamilyID=ca9d90fa-e8c9-42e3-aa19-08e2c027f5d6&displaylang=en thanks sign Lowongan Kerja S1