Hi guys, i have this problem with my imac that is making me go nuts! A couple of weeks ago i failed to install windows by bootcamp and accidentally did a format on my mac os x partition. I couldn't fix the problem so i brought it to a apple reseller to fix it for me, after 3 days, 1 hour and 30 minutes of work and 160 euro bill, my imac was running again. But... Whenever i opened an application or open something else the imac makes noise, like its reading...(probably the HD, that's what i thought). So again i brought it to the apple reseller to fix it. And it cost me 3 days without my imac and 60 euro benzine to fix the problem. They "replaced" the Harddisk(Don't know if they really did it). So the problem should be fixed right? No! it didn't make any noise for 2/3 days but yesterday evening it started again. This noise is only when i open an application or file. So it's not constantly. Could it be an application that i installed? Could it be that the HD again fails? Could it be the reason because i didnt update my imac? Could it be an other hardware part and not the Harddisk. I really dont want to bring it again and pay 60 euro's on gas and i have to go to vacation in a week. But i really want to fix my imac because it was deadsilent. PS: Ill try to record the sound but dont thing ill succeed.