HDMI Image Quality and sound Problems

If you go back to the forum topics list and use the search function to check on "image quality" you'll see that there have been a number of questions about how an HDMI cable effects image quality. The answer in all of those forum topics is that it doesn't.

The HDMI cable takes 1s and 0s and moves them from one end of the cable to the other. If you get errors in the 1s and 0s, then these will show up as sparkles, no image, lines through the image and other obvious things. What the cable won't do is to change the contrast or the brightness or the color. It's just a dumb cable. Really dumb cable.

What you are seeing is that your computer or your TV has a different setting for HDMI than for VGA. It is also possible, depending upon the quality of the video card and TV, that the HDMI input is not superior to that of VGA. This was particularly true of HDMI in the early-to-mid 2000s timeframe. Many people preferred component video or VGA inputs. Another possibility is that you have scaling set to 'on' with the video card when using HDMI. Use your ATI or NVidia control panel to see if scaling is set to 'on' and also change any settings that might be set incorrectly.

Your audio problem is likely on the computer side of things. Probably Windows settings are being reset to a default. Unfortunately, the only thing to do then is to try to find the setting that is being reset and set that to the default setting, which it sounds like you tried to do. Continue down that path.

Also, I noticed that you are new to the AVSForum. Welcome! In the future, however, it becomes easier to answer your questions if you provide more information about your hardware configuration (including model numbers).