What could this be? Defective speakers? I got my motherboard replaced over a month ago as well, so could something be going on there? Maybe a problem with the sound card (I hope not...)?
Eh, this time restarting the computer didn't fix it...
To clarify, the noise isn't a sound from Windows, it's a static-like rapid clicking noise. Also, when I got my motherboard replaced, my soundcard was moved to a different PCI slot. I read that my problem may be that I need to move back my soundcard to the original PCI slot, and then reinstall drivers.