Audio speakers have worked fine since this week. At startup it is working but after a while (15-60 min) it eventually stops playing sound while the programs show that they still play.

However the headphones always work well.
If anyone can tell me a way to do it by registry, by a batch file, etc i would be so gratefull.
What have I done?
Reinstalled the drivers of the high definition audio device.
Installed codec pack for 8.1.
After this not working i restored the system to one week before.
Tried bat file to restart windows audio.
Thanks in advance.