i keep getting error message no mixer divice.
First right click on my computer and in the hardware tab, you shall find device manager, open it.
Now look down in the list for sound devices, and see whether they are working. If there is a yellow tag against them it mean something is wrong with your drivers, perhaps not installed correctly or damaged.
In that case you need to uninstall your existing drivers, by going to control panel, add/remove programs.
Reboot, then reinstall them again.
Also its worth checking that 'Audio Service' is running. You can check this by going to control panel, administrative tools, and services.