Windows 7 USB Driver Jungle

I have an Arduino ZERO that I bought a few months ago. It worked fine. Then I installed Atmel Studio 6.2 and its smart USB support for their SAMD 21. Virtual EDBG USB driver on COM3. A new Arduino ZERO works fine with the EDBG CMSIS-DAP driver on COM10 but now Windows thinks my old Zero is the Atmel board and keeps trying to use it with the Atmel Virtual EDBG on COM3.

I went through driver uninstall/reinstall, but Windows remembers the wrong driver. Is there a way, short of reformatting, to get Windows to recognize my old Arduino ZERO and also let me run Atmel Studio on the same computer?

The Windows Registry is an extreme hoarder.

Problem halfway solved. The Arduino Zero that I bought from http://store-usa.arduino.cc/ on 8/19 has the wrong PID - 2111 .

This is the same PID as the Atmel SAMD21 Xplained board. The newer Arduino from the same .cc site has a different PID - 2157 . All three boards have the same VID - 03EB .

So my question is whether I can set the correct PID of an Arduino Zero or should I ask the store to exchange it?

It's also possible that I could use Regedit to fix it, but that tool is prone to typing errors.

I got the listComPorts research tool from http://todbot.com/blog/2012/03/02/listcomports-windows-command-line-tool-for-usb-to-serial/ , Thank you todbot for blogging this, and thank Google for finding it.