There are no active mixer devices available.

Troubleshooting the Error

When I checked the Sound and Audio Devices section of the Control Panel in Windows XP, it shows there are no audio devices and everything is greyed out.





Then I checked the System Devices section of the Control Panel to make sure the sound card was installed correctly and all drivers were installed. As you can see below, the sound card in this case the Realtek High Definition Audio card is installed and working properly.





Solution

It turns out the problem for this error lies in the Windows Audio Service, which usually starts automatically when the sound card is installed and working. However, in this case the service was turned off. Follow the instructions below to reactivate the Windows Audio service.



There are no active mixer devices available. You may install or activate mixer devices from Control Panel. This application will now exit.

*getting this error when trying to change the volume settings in the task bar icon.. pl help.

1) Click on Start and Run
2) Type the following command and press Enter

services.msc

3) Scroll down to Windows Audio in the right-hand column and double-click on it, you should see a screen similar to this one.



4) Make sure the Startup Type is set to Automatic and click on the Start button under Service Status. The Windows Audio service should restart and the error with the volume control should be resolved.