Using the Package Manager Console inside Visual Studio is the fastest method to safely download and resolve dependencies for your target framework. AjaxControlToolkit 7.1213.0 - NuGet
AjaxControlToolkit v7.1213 up to v20.1.0 .
The definitive methods to locate, download, and install the AJAX Control Toolkit for an ASP.NET 4.5 project include using the NuGet Package Manager or manually referencing the archived binaries. Choosing the Correct Version for ASP.NET 4.5