Hello, I bought a VGA cable for my Xbox 360 today.
I get great video but the audio is bad quality.
I connected the RCA audio cables into another cable to turn RCA > 3.5mm male. I then connected that cable to my Line In on my computer so that I can get the sound to my computer speakers. Now here is the problem: When I'm in the dashboard or game menus the audio is GREAT with my computer speakers but as soon as I am in-game in any game the audio is really bad quality. I can't figure out what is wrong, the only time the audio worked good in-game was in BF1943 when I changed the audio setting to "Home Theatre" inside the game options.
This is the same problem I've been having. I've used my XBOX 360 in the same setup you described and it's always worked on my computer with Windows XP. However, I just recently reformatted and switched to Windows 7 and my audio through my line in is really distorted. It seems like the levels are set too high but I can't find any way to turn it down.
However, on my XBOX, all the sound is bad. Even in the dashboard the sound is distorted.
Sorry I don't have an answer for you, but I just wanted to at least say that this setup did work on a system with XP.