Why can I not record in Windows?
On Windows systems, you may receive "Error while opening sound device" when you try to record. This typically happens when you first use Audacity for recording and have no audio input devices (or only the built-in microphone) showing in Device Toolbar. See Error opening sound device for more details on this error.
If your Audio Host is not already set to MME (the Audacity default) in Device Toolbar, try changing it to MME as this host is the most compatible with all audio devices.
To investigate this further, exit Audacity then on Windows, right-click over the Speaker icon by the system clock and choose Sounds the click the Recording tab. Follow the steps on Windows: accessing the Windows Sound controls to show then enable all disconnected and disabled recording devices.
Many new Windows laptop, notebook or netbook computers only have a single audio input port. This will often be a mono port only meant for microphones. On some machines this single port may also be able to accept stereo line level input which is essential to record from standalone cassette decks or home audio systems. However the stereo quality or separation may be poor. See "How to connect your equipment" before connecting high output devices to a sole input.
Windows 10 privacy settings
For some users Windows 10 is now blocking Audacity from using the microphone, on the basis of privacy settings (and this can also affect non-microphone devices). After upgrading to version 1803, some users have been reporting that the microphone is getting detected, but it doesn't pick up any sound.
In order to get around this issue, Microsoft recommends that you need to enable the microphone in your Privacy settings using these steps: 1) Open Settings 2) Click on Privacy 3) Click on Microphone 4)Turn on the Allow apps to access your microphone toggle switch.
See this Microsoft website for more details.
You may also need to do this if Audacity was working on Windows previously but you now get the "Error opening sound device ..." message.