"There are no active audio mixers" error despite having a functional hardware

Pls anyone who can advise me on how to fix this minor issue.. So I had a windows welcome tune whenever I on my PC.. but after a few minutes, there are no sounds when I watch online or some movies on my pc.. and when I click the audio icon on taskbar, it states that there are no active audio mixers.. So I just go to services.msc and windows audio then start it, then everything's fine.. not until I restart my PC.. it is set to Automatic but it just stops on its own after every restart.. I thought of having a system restore but afraid of what might happen.
 
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