There are two suites of RadControls - RadControls for ASP.NET and RadControls for ASP.NET AJAX and the RadToolTip control is a part only of the RadControls for ASP.NET AJAX suite. The suite is available in
your Client.net account, under My Free Trials (see attached screenshot).
We recommend to upgrade to RadControls for ASP.NET AJAX, because they do not only contain additional controls, such as RadToolTip and RadFormDecorator, but also have a lot of advantages and improvements.