If you are using Bluetooth GPS with USB Bluetooth Dongle connected to your computer, maybe you suffer from to many COM ports each time you connect USB Bluetooth Dongle to different USB port on your computer. This problem make your Bluetooth undetectable by GPS software. I found a solution for this problem after some googling.

First I start by Bluetooth GPS setup then I ll move to maping/removing useless COM port.

Setup Bluetooth GPS
  1. Turn on Bluetooth GPS.
  2. Right click on Bluetooth icon in your taskbar and select "Add a Bluetooth device".
  3. Search for your bluetooth GPS and select it.
  4. Select "Don't Use passkey" for connection
  5. Wait a couple of seconds.
  6. Remember the COM ports and use them inside your GPS navigation software.

Alternativaly you can find Bluetooth GPS COM port by:
  1. Right click on Bluetooth icon and select "Show Bluetooth Devices"
  2. Select "COM Ports" tab
  3. You will find your Bluetooth GPS Connection port there.


How to Remove useless COM ports or re-assign them to other port:
  • Goto Control Panel > System > Device Manager
  • Expand "Ports (COM and LPT)" listing
  • Double click your Bluetooth GPS port.
  • Go to Port Settings Tab and press on Advanced button.
  • Select new port from "COM Port Number" e.g. Port 9.
  • Click on OK to save settings.
  • Now the port number has been change and you can use new port number in you GPS navigator.


Hope to be useful.

Cheers,

Reference:
http://www.pocketpcfaq.com/raj/MSTBluetooth.html