This solved my problem! In a PowerPoint presentation on my Lenovo laptop, I was going to have either a choppy video with sound using a USB A/B cable, or a smooth video with no sound using an HDMI cable. I l followed your directions as best I could--when I right-clicked on my volume control I went directly to "playback devices," not "settings" first--and just picked a different option (I didn't know which one to pick), and set that as the default. I had my Bose speaker connected already when I did this. Then I hooked up the projector to the laptop with the PowerPoint already on the laptop first, and it worked! I had already called a computer IT service first which told me that HDMI was the only connection I had that would smooth out the video, but they didn't know how to get the sound to work. I am overjoyed that now I will have a smooth video with audio in my PowerPoint. Thank you so much!