In WMP, I have been shown buttons on the taskbar thumbnail. How can I make them for my winforms app in C#?
The WindowsAPICodePack contains a control called ThumbnailToolBarButton
that you can use to get this functionality going.
You'll need to make sure you have icons for each of the buttons (as I don't believe you can put text on them), and then it should be a simple matter of creating new controls and adding relevant event handlers.
Sourced from here.