I use a lacie external hard drive and each time I go to the system tray to unplug or eject hardware it says, the device generic volume cannot be stopped right now. Try stopping the device again later. All I can do is to switch off the power. Also when I open microsoft outlook, if the hard drive is not switched on it says it says 'the path specified for the file E:\backup mail.pst is not valid'. What can I do to avoid this message?