Symptoms
Windows computer has no sound
Cause
The volume may be turned down or muted within the operating system.
Resolution
1) See if the speakers' power supply is plugged into the wall.
2) Make sure the input audio cable is pushed in all the way into the computer and is in the correct slot.
3) Double-click on the volume icon in the lower-right corner on the Windows taskbar.
4) On the window that shows up, make sure that the mute button is not checked and the volume is at a reasonable level.
Outcome
Sound should now be restored for the affected Windows computer.