As long as someone is prepared to support you'll be fine with whatever the person doing the support wants. Me personally I think a real serial port is more reliable. I have had to re-install drivers, reboot the computer, etc when using the USB-->serial cable on Win Vista and up. Even with a new machine there is usually a serial port on the motherboard, just connect an internal serial port cable to the motherboard and pull it from the motherboard to an external slot so you can get to it. I'd go that route if this is a permanent need. Serial to USB is best for laptops and temporary use. But like I originally said, 95% of the time USB to serial works fine as long as you're ok with occasionally exiting out of an application and re-entering once in a while, and also unplugging/re-plugging in the USB cable every so often if something goes wrong. Bill