The other day, I had a customer ask to me to fix his sound. This called for Troubleshooting 101; figure out and solve the problem.
First, is there a defined problem? Yes; “the sound doesnt work.”
Second, is the problem hardware, software or both? In this case, both.
Third, check the software:
Is the volume muted? Yes/No
Is the volume turned all the down, or otherwise turned off? Yes/No
Then check the hardware:
Are the speakers on? Yes/No
If no, are the speakers plugged in to power?
Are the speakers plugged into the computer? The correct plug?
Finally, check all other connections. Follow all cords to make sure everything is plugged in to its proper place, including sub-woofers and surround-sound.
If none of this works, then it is time to check for device driver errors. But that is Troubleshooting 102.
As it turned out, my customer had unplugged his sub-woofers power cord, and that had unplugged his speakers. So, I plugged the sub-woofer in and all was well.