I have a Toshiba 1TB Canvio® Slim II Portable External Hard Drive and I am using it on my Mac for my Time Machine storage and when I connect the USB cord it asks me for my password to unlock it and I enter it and it unlocks, then it asks for me to enter the password to unlock TOSHIBA EXT which is the same password and the first one but it tells me my password is incorrect. How do I reset it?