I purchased a new Dell XPS 8900 desktop, 64-bit operating system with Windows 10 Home about a month ago. The computer has never made a sound, whether it's Windows system sounds or sounds associated with programs. No sounds come from either the third-party speakers or the headphones, which work with other computers. So far I've tried the following:
Installed the newest version of the RealTek High Definition Audio driver from Dell website (it's green-checked on Control Panel)
Did speaker setup with Dell Audio Manager
Performed speaker setup and testing through Control Panel > Sound (testing produced no sound)
Inspected cable connections multiple times
Performed audio diagnostics through Dell Support website (the computer failed the first test, the second wouldn't continue because of a specious time zone issue, which didn't exist)
The speakers are plugged into the green jack on the back panel, and the headphones are plugged into front headphone jack. One thing I did do was to edit the registry to install the Windows sound mixer, which was not present in Windows 10. I did add a video card and another internal 3TB WD hard drive to the computer, but none of those actions has affected my old computer.
I've tried about everything I know so far. I believe this is likely some kind of software glitch or conflict, but I can't get the computer to make a sound. Control panel tells me that everything is working normally. Does anyone have any suggestions?