>>>_screen.icon = "iconX.ico"
>>>
>>>I can easy change the Icon dynamically.
>>>Bud the Taskbar always shows the old Icon.
>>>
>>>Is there a API Call to force the Taskbar to do so?
>>
>>Modify your project, and in the menu Project-Project info-Attach Icon
>
>That is not the solution for my Problem.
>I want dynamically change the Icon.
>Like the Outlook Icon, that shows there a new emails...

Dynamically you cannot, my suggestion was a permanent change.