Este nieco kedze si pisal ze to posielas aplikacii ktora nema focus (som to predtym nejak prehliadol), tak SendInput nemozes pouzit (to by malo byt pre cely system), ale mohlo by ti este pomoct GetKeyboardState a SetKeyboardState, to je podla MSDN thread-specific, ak by ti to neslo urobit posielanim WM_KEYDOWN.