I think I know the answer to this question, but I have to ask anyway. I am running 64-bit Windows (Vista or Windows 7) and I cannot get 64-bit drivers for the Microsoft Fingerprint Reader. It is really annoying that Microsoft continues to sell a product for which they refuse to fully support. This is the only piece of hardware that I cannot use on Windows 64-bit edition.
This is the most comprehensive thread I have found to date. I would even accept the fact that it is a hardware limitation, but I just don't understand why they don't sell an upgraded version that supports 64-bit.