MS Streets and Trips says "Your GPS device must be configured to use a COM port below 256, and ports 20 and below are recommended. Ports above 256 are not recognized." So how do I do this being my receiver is a USB device?

Ages ago I had a Delorme Earthmate GPS (USB) and it also needed to be connected to a serial device. It came with a "Serial Emulation Driver" which allowed the usb device to be mapped to a virtual serial port. You might try the support area of the Garmin web site and see if there's something like this available for your model. -- kptech

I also found this at MS Support site: http://support.microsoft.com/kb/952607 See the Garmin section in the above article. It suggests that Garmin USB devices don't support the NMEA 0183 Interface Standard which is required for it to work with Streets & Trips. If this is the case, your hardware is not compatible with Streets & Trips. I think I'd still visit the Garmin support site just to cover all bases. -- kptech