Yes you can use the Ajax components in Visual Studio 2005

milinpaul :

This is post is to ensure can i have ajax programmability and complexity in Visual Studio 2005 especially in .Net framework 2.0

Sure you can..

http://www.codeproject.com/KB/ajax/AJAXASPNET20.aspx 

Here is official ASP.NET Ajax site

http://www.asp.net/ajax/

This site has all the ajax control toolkit demo along with code, you can add this site in your favourite,

Mark this as answer if it helped you