I can't power down my

Question

I can't power down my passport. When I right click on the safely remove hardward icon, click on the drive to close and click stop, it tells me: "The device 'Generic volume' cannot be stopped right now. Try stopping the device again later." I tryed last night and now again this morning. I have nothing else running. I even did a warm reboot and tred again - - same message. I JUST installed my passport yesterday July 31st (it's the first time I'm using it). It's a 160GB drive. S/N wxc208428132