Audio stuttering

Hi all, I've recently upgraded my OS from XP to Vista Home Premium 64bit. Before I switched to Vista, my on board sound was Realtek HD Audio and worked perfectly. After switching to Vista, my audio started to stutter every 10-15 seconds, even with the latest Realtek drivers for Vista. I read that onboard audio uses up more processor power or something similar to that, and that a sound card could remedy that. So I bought a Creative Sound Blaster X-Fi Xtreme Gamer card, installed it along with the latest drivers, and I'm still getting audio stutters. I've tried locating and disabling the on board audio (HD Audio was the only thing I could find) in my BIOS (ASUS P5K-V), but to no avail. I also read that increasing the CPU voltage might help (I tried from 1.28V -> 1.35V, but that did not make a difference...I don't know if that was actually a viable solution or not).

I've ran chkdsk and no problems were found. I don't know if this has any relevance at all, but I have 2 HDDs, one, which my OS is installed onto as well as the audio drivers, is IDE, the other recent one is SATA. Also, whenever my cpu uses resources according to the cpu meter on the sidebar, my audio almost always stutters. It will do it with something as simple as opening a folder.

At this point, I'm at a total loss at what to do, any suggestions/advice would be greatly appreciated.

Note: My tech level isn't too terribly high.

 

My system specs are:
Intel Core 2 Duo E6850 3.0GHz stock
6GB DDR2 RAM
ASUS P5K-V Motherboard
Radeon HD3870