@ABC-King did you install the driver for the RS232 cable? I had to manually download the driver. I have XP and it installed, but didn't work. Once I downloaded a driver from the internet and installed it, worked like a charm. I also just used the cable with a max232 chip, not a whole board like you have, so I had more room for error.
Unplug the cable, check in the Arduino IDE under tools, remember all the Com ports, then plug the cable, check them again. If something shows up after you plugged in, it should work and is probably something else. (make sure you select it, lol
Most rs232 cables will use the same drivers, try installing this one or another one and try again. http://www.wiretek.com.cn/driver/USB%20TO%20RS232%20Cable/USB%20TO%20RS232%20Cable.rar