Is it possible to "mark" my program as active in the windows7 taskbar without actually showing a window and even provide a thumbnail picture? I worte a small program which displays the system battery as a deskband. Now in windows7 I'd like to display the battery in the thumbnail picture, and make the deskband optional.
Yes, it is possible. You need to make your window permanently minimized. You can provide anything for the window's thumbnail.