Manual Method: Update Realtek audio driver through “Device Manager”
1) Go to Device Manager.
To Start Device Manager
Open the “Run” dialog box by pressing and holding the Windows key, then press the R key (“Run”).
Type “devmgmt.msc” in the dialog box like shown below
2) Expand category “Sound, video and game controllers” by click the arrow that is point right as seen below. Under this category, right-click on “Realtek High Definition Audio” or “Realtek Audio”. Click Update Driver Software on the menu.
3) Click “Search automatically” for updated driver software.
If the driver is up-to-date, you will be notified that “The best driver software for your device is already installed”. Then you don’t need to update the driver.
5. After the driver is installed, restart your computer for the changes to be fully implemented.