16 com ports WTF am I doing?

So I am having some major COM port issues. I have no clue what is going on, but I am up to the point where I have com port 1,2 and 10,11,12,13,14,15,16... My port 10 is GPS and 15 is OBD2... But my OBD program only shows Com port 1-8 so I cant actually use it. How can I go back erase all of my COM ports?

USB devices add to your com ports.
Reassign the one that your OBD is using to one in the range that your softare will recognize.

So how do I reassign them though? Because it automatically assigned those values to them. I thought I had to go through the registry and change some values to 0.

Change the COM port assignments in the Device Manager.