Not all cables work, and some cables can work a little but not entirely. The cable isn't so much a cable as it is a computer in itself that translates between the bike and the PC. I wouldn't make any changes to anything whatsoever in your shoes until I got TuneECU to load properly and show proper data, or else you can do all kinds of interesting things.
Where did you get the cable, and does it have the required FTDi chipset? Did you download the latest FTDi drivers and install those on the PC?