My newer HP laptop has no built in serial ports. The EZ-Steer update procedure requires hooking the EZ-Steer cable to a serial port in order to reflash the controller. Last year, someone recommended the Keyspan USB to Serial convertor.

I'm running Vista home premium on my laptop and the convertor worked flawlessly to upgrade the EZ firmware. Model I'm using is the USA-19HS. I had tried a couple other brands and they didn't work at all for this. Keyspan works well.