Configuration of 260 To Laptop Via USB - Serial Adaptor

I am having trouble configuring my 260 to my laptop. I do not have a serial port on the laptop so i purchased a usb to serial adaptor. When i open driveware it tells me there was an error locating the com port and does that for any com port I set it to. At this point I can not connect my 260 to my laptop but I can connect it to my PC. I do not know what com port to set it to because I do not know which com port the USB is. Can someone give me some advice???