Computer Noise Through Speakers?

My computer is only a year old at least and recently has been making weird scraping noises through the speakers. I don't know how to solve the noise problem because I'm not a tech guy.
The noise come and goes... And sometimes the noise is pretty loud for a few seconds. What's wrong with my speakers?

If you have an integrated audio chip, I would check the mfg. website for updated driver software.
If a pci card, try it in another pci slot.
I have experienced similar problems and moving the card to another slot was the solution.

If your sound card supports Digital Audio output, you can try disabling that to see if it helps. You should also make sure that the Microphone / Line-In on your sound card is disabled / muted, as this can cause feedback noise, too. Disabling the digital audio output and muting 'input' ports should be accessible through Control Panel -> Sound (you may need to click an "advanced" button, or similar). Note that not all audio cards have the same "options" layout, so it is only possible to generalize the location of these features.

This solution works for some people too. Go to:

Control Panel -> Sound and Audio Devices -> Advanced -> Options -> Properties -> Lock PC Beep -> OK

Now mute PC Beep and it should be working.