I just got my first Win7 PC going and had the same problem.
My problem is the control panel does not show a driver name, you just got to go the the drivers folder and try. Yes, this is the folder above the FT drivers. You don't get to actually pick a file name. Just send W7 off hunting for the driver after bypassing the warning.
Works fine now on W7 64 Bit.
Thanks for the tip.