This example shows how to show progress on taskbar icon, set tooltip for thumbnail, choose thumbnail RECT, add buttons to thumbnail (with event handling) and add overlay icon. Also this is an example of working with COM objects using there GUIDs (https://www.vbstreets.ru/VB/Articles/65974.aspx). And finally code shows how to subclass window in an object module (using ASM). Unfortunately i don't know the author of this method. P.S. thanks to Sharp and EROS.