Computer (the speakers) emitting periodic noises (like folders opening/closing)

Every once in a while my computer speakers emit a sound that I can only liken to the sound you hear when opening and closing folders (in, say, MyDocuments), a sort of clicking/door-opening-and-closing/shuffling noise. It happens seemingly randomly and intermittently--every couple of weeks, for instance. It's happening tonight at very random intervals...once or twice in a single minute, for instance, then not again for another thirty minutes and then silence for another ninety minutes and so forth...It wasn't happening at all earlier in the morning or afternoon.

This sound is not coming from the actual computer itself. It is not hardware related, in other words. I've tried to fish around for advice before and people immediately assumed it was the HD or disc drive. It is definitely software related; I can control the volume of the noise by adjusting the volume on my computer, for instance.

I know this is very vague but perhaps somebody can point me in the right direction. I've tried closing all programs but the sound persisted. This may seem rather paranoid, but could somebody be using a trojan to remotely rifle through my files or something? I don't see anything odd in the Task Manager.

 

If, i am not wrong, its windows system default sound, you can set it from control panel- open sound & audio device- select sound- from menu you can change to none or any other sound.

Edit: Aww i just realize, its happening automatically, did you tried full system scan, it might be spybot or someother problem. use spybot search & destroy software or anyother one and scan your system.