There are no active mixer devices available when opening volume control
Although the sound card and its drivers are installed correctly. I receive this error message about no active mixer devices when I try to double-click on the Volume icon in the system tray of Windows XP.Most people will assume the sound card itself is having difficulty or the drivers have no been installed, or maybe the system has been muted. However, when the computer starts or shuts down you hear the normal Windows sounds. However other audio does not play normally and results in error messages.
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.
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.
