Sound cutting out randomly

Alright so I recently built a new pc, specs listed below. The computer has had a problem from very early on though with sound cutting out. For instance, after listening to music for around 20 minutes, I will hear a high pitched sound and then no audio. When I go to WMP, it just shows an error saying that an audio cable may have been uplugged, etc. The same thing can happen when watching videos or when playing video games as well. Usually it's the same thing, high pitched sound and then no audio until I either restart the application, or in more severe cases, restart the computer. If I play two forms of media simultaniously, for instance a game and music, it happens almost instantly every single time.

This is driving me INSANE. :banghead: Now, when I built the computer, I tried installing a sound card but it was giving me problems. Well once it was determined to be DOA, I just decided take the refund and use on board audio because I have the Bose Companion 5 speaker system and it sounds great anyways. However, in my Device Manager I have an "Other Devices>Unknown Device" that shows up. This is where I think there could be the error, as the sound card was having driver issues as well, making me think that this unknown device could be the cause of the problem, perhaps causing a conflict.

My current devices listed under "Sound, Video and Game Controllers" are:
Bose USB Audio (the speakers I stated)
High Definition Audio Device
NVIDIA High Definition Audio
Realtek High Definition Audio

The fact that there are four devices showing there also confuses me and makes me again think there is something that is conflicting.

Any ideas would be greatly appreciated!!!


Build:
Windows 7 Home Premium
Intel i7-3770k @ 4.2GHz
16GB GSkill Ripjaws 1600 RAM
Nvidia GeForce GTX 670 FTW Edition
2TB 7200 RPM Data Drive
120GB Corsair Force Series SSD
ASRock Z68 Extreme3