If your windows 8 is being updated to 8.1 & you are facing a problem in which the volume does not work,then dont worryits nor a big deal you can solve it in seconds :)
All you got to do is :
1) go to the Device Manager and select the volume producing driver in my case its realtek system driver which is the volume source of my system.
2)Double click on it,you will get 4 tabs instantly.
3) Just go to the drivers and uninstall it for the time being.
4)Now,its the time to reboot your pc once .
5)When it restarts your output audio is ready to provide you realtime music go boom boom again :)
Catch: you must be wondering how did it work ?? although i have uninstalled it??
actually you have temporarily uninstalled it,once you reboot or start over the pc,the system
files are again reconfigured and thus becomes ready to use again.