Some users have been experiencing problems with a "No Audio Output Device Installed" error when trying to play music, or when hovering the mouse over the speaker icon in the system tray. You may get a white X in a red circle to indicate this error.
Go to the device manager by pressing WINDOWS KEY + R to go to the run menu, and then run " ".
From here, select your malfunctioning audio device(s) and make a note of the driver name. Then, right click on it and select Uninstall. This will remove the audio drivers from your system.
Once this is done, re-load the drivers for your sound card from the CD your manufacturer gave you with your PC or sound device. If you cannot find this, search for the driver on the manufacturers website using the driver name that has been written down.