I have it working on Windows 8.1
The trick is that you have to use an older FDTI driver than the one Windows automatically installs.
I got the 2.10.0.0 driver from here:
[Link: ftdichip.com]
I could not get Windows to let me install the older driver so I used the "Driver backup and restore function" in the DriverMax freeware software to force the install of the older driver. I think you could also use Glary Utilities to do this.
The IRClone device is listed as "USB Serial Converter" in Device Manager.