Every time a USB device that represents a COM port (such as the BSF-7-USB) is plugged into a different USB port of a computer, a new COM number will be assigned. If you change USB hubs there’s a whole new set of USB ports!.
Eventually there are no numbers left below 16, but SI-Config needs the COM number to be below 16.
The following trick allows you to clean up the unused COM ports:
First start a Command Prompt session in Administrator mode (right-click on the Command Prompt link in Start Menu | All Programs | Accessories, and select Run As Administrator).
type in the following commands:
set devmgr_show_nonpresent_devices=1
start devmgmt.msc
Once the device manager starts up, there’s an extra menu item in the View submenu.
Select it so that the checkmark is there.
Now expand the Ports (COM & LPT) section to see all COM ports.
Now you can select an extra COM port, and uninstall it.
I do not delete the drivers for the device:
Insure you don’t delete anything important! You’re in charge, I’m not.
After I deleted all the SPORTident USB to UART Bridges, I inserted my BSF-7-USB, and the computer now had to re-install the driver (but I didn’t have to download it again). Once the installation was done (took about a minute), I now have it installed on COM4. All is good!
[Thanks to digi.com for coming up with this trick]