My HDD (40GB Samsung) started making this whirring sound suddenly during normal operation... although the system is working fine but the noise is quite irritating...! pls. prescribe!!
the buzzing or 'whirring' sound is usually caused by the bearings and if its a constaint noise it will normally only get worse w/time. you might want to make sure the drive is secured in tight, could just be vibration. i would give it a little time, if it does get worse (depending on how old this drive is) call the company and get it replaced.