Being most of us are not mind readers , and it seems your using a Pro-97 scanner , what interface cable are you using ,what software are you using and what computer system are you using (windows 98 ,xp ??)
Do the lights in the amber box on the data cable light up? If not, get into Win 97, click on "configuration" and figure out which port you need to be on.
Go to control panel > system > hardware > device manager > ports ... and see what COM# port has been assigned to the cable. Put that port # into the software and try again.
Please note on the cd with the rs usb cable is a manual on how to unstall and use the cable,
step by step instructions and troubleshooting in pdf format