Windows 10 error opening or Internal PortAudio error[SOLVED]

Thanks, Robert. So it is not entirely to do with WDM-KS.

You might possibly find that 2.0.2 Audacity download latest version does not have this issue - some changes we made for 2.0.3 to improve audio device behaviour on Vista and later apparently introduced quirks on a few machines.

Gale

Further discussion about WDM-KS split to:
Providing a build with WDM-KS support - Windows - Audacity Forum.