I am one very frustrated user!
I’m on a Windows 7 64 bit system. I was using Audacity version 2.0.6 without issue but at some point I started receiving this “Could not find any devices” error.
At the time I was only using it occasionally so I can’t be specific as to what might have been done that “screwed the pooch” so to speak. I have a rather complex audio setup (on a scale of 1 to 10 it’s probably 6 or 7) that uses one of 2 SPDiF outputs. I have a quad core 8GB RAM system with a projector for my home theater, using an Nvidia graphics card with HDMI out, an Asus mobo with its own HDMI and SPDiF out plus 7.1 audio capabilities. I had a devil of a time getting Windows Media Center to use the mobo SPDiF out, and even now the volume control within WMC doesn’t work, I have to pop out to the main sound control in the system tray. That’s just how wonderful Microsoft is 
To resolve the WMC audio issues I installed the Shark Codec (http://shark007.net/index.html) tools which resolved the problem. I believe the issue has to do with the fact that computers with both optical and analog audio use separate pathways to process sound, and the APIs don’t address that very well. ffmpeg can help with that but it is a rather complex piece of software and configuring it isn’t for the faint of heart.
I can’t say that audacity stopped working when the shark codecs were installed, it could have stopped with a windows update for all I know. But I have now spent over 2.5 hours trying to trim an MP3 file and this post is my last attempt in a chain of issues that need to be resolved to accomplish that.
There is very little info about this error I can find online, including Audacity FAQ, its manual and the developers of the PortAudio library Audacity utilizes. Hence my high level of frustration. Even without audio device support I cannot achieve the same level of quality / size when I export an MP3 from Audacity (I can use Audacity without any audio devices to do gross editing, but clearly that’s not ideal).
I have an MP3 recording made with a Sony portable recorder set on it’s highest quality setting. I need to save the first 47 minutes of a 3.5 hr long MP3 file that is 25MB in size. No matter what combination of options I try I cannot get Audacity to expprt an MP3 file that is smaller than the original. I need to upload it to a server and the max size is 10MB. So this is yet another item contributing to my level of frustration.
If anyone has suggestions on how to address the “no devices found” issue related to PortAudio or how to save the first 47 minutes out of the original 3.5 hr MP3 file to produce an MP3 of less than 10MB I’d sure love to hear from you.
Thanks.