In my WIN7 machine I am unable to locate under the board manager a Due. Lots of Arduinos but no Due. I installed v1.6.7 in a WIN7 machine because I could not get a WIN10 machine to chat with the board, even though it did list a Due under the board manager.
Now two different failure modes for WIN7 and 10!
In my WIN7 machine I am unable to locate under the board manager a Due.
Have you searched for it?
There are long lists of Arduino boards under Tools in both the WIN7 and WIN10 versions of the v1.6.7. The WIN10 version lists Arduino Due (Programming Port) and Arduino (Native USB Port) separately at the bottom of the list and separated from the others by a horizontal line. Odd. The WIN7 version does not show any of this.
My WIN10 system makes happy sounds when the USB cable is plugged into the Arduino Due but running a compiled example, Blink, generates an error "No device found on COM1". Odd since under Tools>Port is COM3 (Arduino Due (Programming Port)).