I have the same issue on Win8 ... Before you try anything, make sure you have copies of data from the drive, which should be possible on your Win8 machine.
One way may be to get rid of all drivers and instances in Vista with the drive disconnected ... on Win XP that was done by opening a CMD window,
typing set devmgr_show_nonpresent_devices=1
Go to the view tab and click on show hidden devices. Scrolling through each option will bring up greyed out references to the drive and delete each one.
You will be surprised at te number of uninstalled/not-present USB devices.
It should force a reinstall of the drivers next time the drive is attached.
I am about to try it as I have a problem with a Nokia phone - I have lost file manager access to it although I can use te Nokia Application to update contacts, copy images off &c.
M H C
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