How interesting. I went browsing on the AMD site and their little sub-section of forums and found someone having the same issue with a Radeon HD 4xxx card.
They had the same issue, where the card would make things slow, and if they took it out, it worked just fine.
They solved it by going into device manager -> System Devices -> and disabling High Definition Audio Controller. Why it's that, I have no real clue.
I didn't have the same card, but, figured it was worth a shot. So I went and did it.
Immediately after, I was so relieved. It fixed the issue. My CPU usage went down to 10% and doesn't go any higher now when its idle. Windows 7 is now running smoothy, speedy, and snappy, the way it should wewt! haha, i'm excited