I have a teensy 2.0 connected to a stepper motor shield and motor. While debuging some software I got a driver update notice which I clicked to install. Now, when I connect the Teensy to my laptop or my desktop computer, the Device Manager shows it as Portable Device, E:\ instead of an entry in PORTS and COM, and I get an AutoPlay window for Removable Disk (E:). When I click the 'Open folder to view files' button it lists a Readme.txt file. The contents of that readme are:
"This USB disk was automatically formatted when you compiled your sketch.
You can place files to be copied onto this disk, instead of this Readme
file, in a "disk" subdirectory inside your sketch. That location
would be:
C:\Users\Weber\Documents\Arduino\IRteensey\disk
For a blank disk, just create that directory but don't put any files
into it. To name your disk, create a file ".VolumeLabel" with the name."
Apparently the driver I allowed to download has overwritten the USB/Serial software in the Teensy. What program is loaded in the Teensy's ATmega32U4 that provides the serial interface to the USB? HalfKay? Can I install it? What do I need to do it?
Bob Weber

