Du benutzt echte Desktops? Also mit CreateDesktop? Dann kannst du mit SetThreadDesktop und SwitchDesktop arbeiten.
SwitchDesktop schaltet auf den erzeugten Desktop, SetThreadDesktop assoziiert einen Thread mit einem neuen Desktop. Aber Warnungen beachten.
Zitat:
The SetThreadDesktop function will fail if the calling thread has any windows or hooks on its current desktop (unless the hDesktop parameter is a
handle to the current desktop).
Warning There is a significant security risk for any service that opens a window on the interactive desktop. By opening a desktop window, a service makes itself vulnerable to attack from the logged-on user, whose application could send malicious messages to the service's desktop window and affect its ability to function.