I can also confirm, the ProtoEdit software will run on 64bit but, the driver will not run, so you can not connect your pronto to the PC, you will need a 32bit OS.
I actually have a XP VM (VMware player) to use for this on my 64 bit os....
BTW, on the preview of Windows 10, this software does not run at all, on 32bit or 64bit...