This post was in response to a now banned user who was posting questions copied from other users
Audacity needs proper drivers meant for Windows 10 and matched to your devices. Simple playback might work even if that is not the case, but recording or recording with playback will not, and Audacity has to check for that when it launches. However there is a problem in 2.1.2 and several version before that even if only one audio device or subdevice has incorrect drivers, Audacity then cannot find any devices. This is now fixed in our current development code.
So you may need to update the drivers for your audio devices to Windows 10 and/or use Audacity 2.1.3-alpha until 2.1.3 is released. For full details, please see our Windows 10 “Wiki” page: http://wiki.audacityteam.org/wiki/Windows_10_OS#Sound_Device_driver_requirements_and_problems.