by
bilal shaik , HARDWARE & NETWORKING , CD EQUISEARCH
AJAX is a built-in functionality of .NET Framework4.0. Therefore, you can run an AJAX application by just installing Microsoft Visual Studio2010. However, to use extenders in your applications, you are required to install AJAX Control Toolkit and copy the AjaxControlToolkit.dll file to the Bin directory of your application.
or
You would need to install ‘ASP.NET AJAX Extensions’ on your server. If you are using the ASP.NET AJAX Control toolkit, then you would also need to add the AjaxControlToolkit.dll in the /Bin folder.
Note: ASP.NET AJAX1.0 was available as a separate downloadable add-on for ASP.NET2.0. With ASP.NET3.5, the AJAX components have been integrated into ASP.NET.