I know there are a lot of posts like this, but I haven't found one exactly identical to my problem, and no fixes have worked.
Problem: Sound makes skipping/crackling noises while playing MMO/RPGs.
This does not occur with (For example)Starcraft 2, which is a RTS game, same with Civ 5. However, it does occur with games like Rift and even KOTOR, which was released around 2002; same exact issue. This leads me to think it isn't a compatibility issue. My FPS is pretty nice too. It runs about 30-60 on new games.
All drivers are up to date; it's been checked several times.
Info on the system: The computer was doing this right out of the box. I bought it cheap and augmented it with a Video card and a larger PSU(from 250w to 500w) so that I could play newer games. I initially thought it was an issue with Rift, but soon learned otherwise. (Since it only happens while gaming.)
Next I figured it was sound card related. I started with the onboard. I updated it with no change. I then used a USB card I had laying around. Same issue occurred. Then I bought a decent PCI card, same thing. So I'm going to assume this isn't for lack of a sound card or driver related. I'm no longer convinced it's even a sound related issue.
Here are some specs for your enjoyment:
MS Windows 7 Home Premium 64-bit SP1
AMD Athlon II X2 255 (3.1 ghz)
4.00 GB Dual-Channel DDR3 @ 533MHz (6-6-6-19)
LENOVO Tilapia CRB (CPU 1)
NVIDIA GeForce GTX 460
SB X-Fi Xtreme Audio (Creative) PCI Slot
Here is a DxDiag as well. Any helpful input would be greatly appreciated.
Edit: Observation, this problem does not occur constantly. It only occurs during loading screens and when I'm running, i.e. movement in the game. Everything is peachy when I'm standing still.