Your port is "probably" no good. You need to go to the shack and get a Usb to serial connector. But then again i am quite drunk right now so i could be wrong!! :lol:
Since the scanner has no COM ports, no, you cannot. Your PC's com port settings are settable in your PC. I wouldn't expect instructions for your PC to be in the scanner manual. If it had to include instructons for everyone's PC, it would be about 3 feet thick.
Check to be sure your cable is plugged in completely.
If you are tring with windows on try rebooting. I just had to do the same when I was setting it up on a friends laptop.
Also try turning the radio off and back on while it is hooked up.
Radio shack had 2 different types of cables at one time not too long ago. One of them was junk and the other worked fine (my experience) I still have both-the junk one I own is black , the good one beige.