I downloaded Microsoft AJAX Library 3.5 from http://www.asp.net/ajax/downloads/

Where do I extract MicrosoftAjaxLibrary.zip to?

What is your scenario?  Basically that download is just the script files that are included with VS 3.5 SP1, so you can drop them directly into your web application and reference them if you're not using 3.5 SP1.  The easiest way to use the scripts would probably be to simply use .NET 3.5 SP1.

 You could extract to any folder you like but after extracting, reference the AjaxControlToolkit.dll in your web application.

@Jim Wang:

I already installed .NET 3.5 SP1.  The AjaxControlToolkit.dll was not in the "bin" directory.

@RemithR:

I downloaded AjaxControlToolkit.dll from http://www.codeplex.com/Wiki/View.aspx?ProjectName=AjaxControlToolkit

The AjaxControlToolkit.dll is now in the "bin" directory.  I copied all files to a MicrosoftAjaxLibrary directory in the "wwwroot."  Is this what you mean?

Hi

If you already have .Net 3.5 framework and its sp1 then you wont have to worry about the asp.net ajax framework . Its a part of .Net 3.5 framework . Yes if you want ajax control toolkit then you will have to get the dll's and add them to your application .

 Refer here

I have explained how to use it in this tutorial

http://www.aspsnippets.com/post/2009/05/16/AJAX-Control-Toolkit-Color-Picker-Control-in-ASPNet.aspx

If you don't have Microsoft Visual Studio, where do you put the Microsoft Ajax Library?

 In the BIN Folder of your website