I use the same type of cable. You gotta have the driver. Do a google for "usb to serial driver" and dig around some. I can't remember where I got mine last time I installed it, but I'll look this evening after I get home and see if I can find it again, if you don't find it first. I do remember last time I got it it was a really small file and I found it through google via some forums.
found it, try this one.
http://www.dvdr9.nl/driver.zip