The control just does not appear in the destination solution.
If you want to copy/paste Telerik`s controls from one application to another, you need to reference all necessary assemblies. For example, create empty WinForms application, add reference the following assemblies Telerik.WinControls, Telerik.WinControls.UI, TelerikCommon, Telerik.WinControls.GridView and after that copy/paste RadGridView from another application.