Rosin, there’s a sound adjustment on the screen while the video is playing. You may have inadvertently lowered the volume there, independent of your computer volume. try putting your pointer over the 4th icon from the left on the video screen (looks like a speaker sort of) – you’ll see a little slide show up to the right of the icon that you can point at. Move it all the way to the right to increase the volume. Try that anyway, I’m not tech support, just a fellow student who has already dealt with this problem. Good luck!