I have HP Pavilion p7-1414, external speakers, Windows 8.1.
This morning I had red "x" thru speaker icon and no sound from speakers. Control panel said "no device installed". Ran Troubleshooter and it did not find any problem. HP Support assistant said to download update for sound. After that, red "x" went away but still no sound. Got message to disable what had just been downloaded, still no sound, then the troubleshooter found it was disabled and "fixed" it by enabling it again, still no sound from speakers. Green speaker jack is plugged into green jack on back of PC. I've shut down, disconnected speakers, etc. - red "x" is gone but still no sound from speakers.
Thank you!