The issue I am having is that my microphone setup is outputting a squealing noise. I can describe it as a high pitched, frequency sound, that changes pitch constantly, kind of as if you were to wave both of your hands frantically in front of a Theremin. I can hear the sound when recording using adobe audition or other audio recording software, as well as when using "Ventrilo", or Skype. The pitch or prevalence of the issue seems to be random, but at times it seems to be related to how hard the computer is working on a task. For example, I have tested in the ventrilo program to find that when i'm looking at my desktop/browsing the web, the output will have the frequency very loud, but if I open a video game full screen, the noise completely disappears. I have a $200 condenser microphone connected to a behringer mixer, outputting through a 2 headed XLR cable (left and right channels) on one end, to a 3.5mm male end on the other end of this cable. This 3.5mm end has a 1.4 inch adapter on it, and connects to a Audiobox USB 2.0 recording interface, which connects to my desktop computer. I have tested in the same room, connecting this audio setup to 2 different laptops. Neither laptop had the issue. I've also bypassed the mixer and all of the crazy cables - Connecting the Mic to an XLR cable to the Audiobox interface, straight to the PC using USB 2.0. I have re-installed drivers and windows several times, even using Windows 8 for a short time, and back to Windows 7. None of these tests resolve the issue (except for using a different computer). At this point I believe it is the hardware on my PC. This is where I need some assistance, or I'm hoping someone else has experienced this. Is it possible it's the motherboard and the USB ports on it having an issue, where frequency sounds bleed through? Could it be the power supply, and why would it be the power supply? Any other hardware that you can think of? Since having the issue I have replaced the hard drive, and the RAM.