when i click turn off computer in the start menu the[stand by , turnoff ,restart box ] does not appear. I have Dell xps 400. I just quickly touch the shutoff button and the computer shuts down normally. If i do not run my Yahoo browser the box will work. If I go on line and browse a little then log off my browser and completely shut off my modem I can not get the shut down box to appear. When i touch the shut down button.,even though I have logged of and shut off my modem,a box appears and tells me my browser is shutting down.