Go in safe mode Open device manager and uninstall the Realtek driver, and the Microsoft HD audio driver, then reboot in safe mode again and install the realtek driver only from here, and be sure if it does work for you to not install the MS one via windows update >>>
Realtek
If it does not work which it should be sure you have you installed the latest Inf installer from intel? >>>
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And ya know, A BIOS update may also help. How many behind are you? If you do flash it, do it in Qflash via USB or floppy