Step 5: Update the Nvidia drivers manually
Troubleshooter on Windows detect problems and issues and recommends solutions on how to fix them.
Try Enabling Onboard Sound Device in BIOS to help fix solve the issue.
Onboard sound devices are automatically disabled when an external sound devices are connected to your computer or when a new graphics card driver has been installed.
If it is grayed out, this means that graphics driver was not recently update and or there are no back up files to roll back to.
At Driver tab, Locate Roll Back Driver button.At Properties window, Click on Driver tab.Right Click on the Display Adapter and Click on Properties at the drop down menu.A list of Display Adapters installed on your computer. At Device manager window, click on Display Adapters to expand it.At Run dialog box, type “devmgmt.msc” and press Enter or click OK to open Device Manager section.Press Windows Key + R on your keyboard to open RUN dialog box.This step involves installing the back up files of the driver before the update and installed it again to your computer. If you think this is what’s causing the issue you can try to roll back audio drivers to help fix the issue. There are other users experienced the issue with Audio No sound right after latest drivers are installed. After changing Audio Output device, check if Nvidia High Definition Audio No Sound problem still occurs.