Assuming you are using Visual Studio 2008 and ASP.NET 3.5

1. Download  from  Codeplex.

2.  Extract the zip file to a convenient location  say  C:\AjaxControlToolkit

3.  Open up Visual Studio 2008 and Create a new ASP.NET Website.  Name the site as myAjaxSite

4.  Once website created, Right-click anywhere on Toolbox and choose “Add Tab”.  Name the tab as AjaxControlToolkit.

5. Now right-click anywhere on AjaxControlToolkit region and select “Choose Items”. That will bringup ‘Choose Toolbox Items’ window.

Select  ‘Browse’ and select “C:\AjaxControlToolkit\SampleWebSite\Bin\AjaxControlToolkit.dll”.  Then Click “OK”. It will add all AjaxControlToolkit controls/Extenders to Toolbox.

6. Now you are ready to start using AjaxControlToolkit.

In Part -2, we will start building Ajax site….

Problem 1 : This page is missing a HtmlHead control which is required for the CSS stylesheet link that is being added. Please add <head runat=”server” />

Solution :  make your HEAD tag  to <HEAD runat=”server”>

problem 2 : The Controls collection cannot be modified because the control contains code blocks (i.e. <% … %>).

Solution:  Looks like you are using <% tags in your HEAD section code like Javascript code etc…. To fix it wrap your head section with <div runat=”server”>  and </div>