Onboard sound card makes occasional buzzing sound, USB sound card breaks up intermittently

[drb01]

I have had the above problem with Win 7 64 bit ever since changing the mobo to a Gigabyte GA-H77m-d3h and re-installing from scratch. Using the onboard sound I get buzzing sounds that last for about 1sec every couple of minutes. So I tried a cheap USB sound card and I get something similar, although rather than buzzing the sound breaks up regularly. This happens when I am doing nothing, but all I do anyway is excel, word, chrome.... nothing hardcore! I have used two players - Foobar, and a Logitech player.

I have got the latest mobo drivers, everything else works well.
Win7 64bit Home Premium
8GB memory
128GB SSD, 2TB HDD

Any ideas? Really don't want to re-install from scratch if I can avoid it ...

 

[drb01]

After months of trying to fix this I finally found the culprit. It seems to be the iDrive backup system. Disabling the Continuous Data Protection has stopped the sound problem altogether. Makes me wonder what other side effects there are ...