Using pyGtk I created a window without decoration. The Window is hidden from task bar and top of all windows. On linux it works fine, but on MS Windows window sometimes it hides under some other window and always has "python.exe" the taskbar in windows.
Image representing my problem:

How can I hide this "python.exe" window from taskbar?
My code:
class Infowindow(gtk.Window):
'''
Klasa okienka informacyjnego
'''
def __init__(self, json, index, destroy_cb, device):
    gtk.Window.__init__(self)
    self.size_x = 260+48
    self.size_y = 85
    self.separator_size = 10
    self.set_type_hint(gtk.gdk.WINDOW_TYPE_HINT_SPLASHSCREEN)
    self.set_decorated(False)
    self.set_property('skip-taskbar-hint', True)
    self.set_opacity(1)
    self.set_keep_above(True)
    self.add_events(gtk.gdk.BUTTON_PRESS_MASK)
    self.connect("enter-notify-event", self.__on_hover)
    self.connect("leave-notify-event", self.__on_leave)
    self.connect("button_press_event", self.__on_click)
    self.set_size_request(self.size_x, self.size_y)
    color = gtk.gdk.color_parse('#f3f3f3')
    self.modify_bg(gtk.STATE_NORMAL, color)
    self.expanded = False
    self.index = index
    self.destroy_cb = destroy_cb
    self.json = json['data']
    self.system_info = False if 'system' not in self.json or not self.json['system'] else True
    self.device = device
    f = gtk.Frame()
    self.move_window(index) #move window to specified place
    self.box_area = gtk.VBox()
    self.box_area.set_spacing(10)
    f.add(self.box_area)
    self.add(f)
    self.show_all()