I think I saw this once - your problem is that you have installed the drivers - so windows installed your drive in some sort of 16-bit "comp. mode" and it needs another 16 driver to finish the comp. installation - try removing the drivers and let windows auto-detect your drive.
I saw this kind of problrm once - but i am not sure that my solution will help you - you may even need to re-install windows (at the worst case when the registry is so screwd by windows that it can't "fix" it - but this situation is VERY rare)