My Passport 500gb ext drive fails to show in my Computer on my Vista laptop. Laptop will not boot to windows unless or until I disconnect the drive. Once running I connect it but can't see it until I unplug it, then it shows up momentarily as the external "E" drive, then goes away. My win 7 desktop will boot while the drive is connected but shows in Computre as a local drive and crashes Win explorer when attempting to access the contents. Drive lites oAre blinking and the platters are spinning normally. Does anyone have a clue how to resolve this issue?