Both audio playback through the integrated sound card AND recording through the USB microphone stopped working suddenly for no apparent reason on my Dell XPS 430 running Windows 7 Ultimate 64. One day it worked fine, the next day it didn't work at all..
It is definitely not a device driver issue for the following reasons:
1. I have done several system restores to days and weeks previously when the devices definitely worked.
2. The USB microphone does not require audio drivers - it has its own audio circuitry fully independant of the sound card.
3. In Device Manager all of the audio devices are listed as fully present, fully working and fully enabled.
4. The speaker next to the clock is present and does not have a red cross through it.
5. Also: Sound is full enabled in the system bios and the Windows audio service is fully enabled and running.
If I launch an audio track through the sound card or a recording through the USB microphone the sound bars against the device in Sound Manager do not move.
If I launch Audacity there is an error message that no audio devices are found. Same for all audio applications.
So in summary:
Windows recognises all of the the audio devices as fully present, fully enabled and fully functioning.
Windows applications cannot find any of the audio devices, sound card or USB.
It cannot be a device driver issue for the reasons mentioned.
Any ideas please?