I came accross this problem several months ago whilst on a call-out for my computer repair workshop.

The owner was complaining of his computer being slow and making "dunk" noises repeatedly, even when idle.

On inspection the slowness was due to an excess of programs running at startp, easily solved by Mark Lin's excellent http://www.mlin.net/StartupCPL.shtml(external link).

This left the windows "no" noise problem. Similar to the way Internet Explorer/Windows Explorer repeats the clicking noise when going through websites/folders, his PC was repeating the error noise at high speed, cutting off the noise before it to produing a never ending dun-dun-dunk-dunk-dun-dunk-dunk.

If this is happening, quickly open Start -> Control Panel -> Sounds and Audio Devices - > "Sounds" tab. If the selected "Sound scheme" is not the normal "Windows Default", change it back, click the "OK" button,  and the noise should stop.

I hope this comes in handy for the few people having this annoying problem.