Windows 8.1, WMM 2012; regardless of what was used to record the video. Various low level background sounds such as fountains/running water, (or even, absent any foreground dialog, just the ambient audio background) is obviously pixelated. It sounds like a cartoon computer processing sound effect, it draws attention to itself, and I've never come across this in any kind of audio recording. Certainly on W7, never was an issue. Do you think I need a sound card upgrade?