Hi.
I just registered to thank you, Glenuth. Honestly, I love you.
My case was somewhat similar. Seems to be a problem with Windows updates from a version to another. In my case, I updated from 8.1 to 10, and after a lot of rage due a lot of problems that resolved themselfs after like 10 restarts, I tried to listen some music, then I noticed this thing. I tried my headphones in my phone first, since they are a bit old but the problem wasn't there. I tried updating all my drivers from the Hp page, Amd page, Realtek page (btw, I think it's a very good option to download the 8/8.1/10 version of the drivers) and Windows page, but nothing. Since I record with my Pc and Im a audio-freak, this was totally offensive. I had been since yesterday's afternoon trying to fix that issue, and your's worked perfectly. I do notice a bit of less quality than when I had 8.1, but it's way better now than it was an hour ago.
Dude, srsly, I love you.