I have this little problem regarding a random sound that started in my HDD some time ago.
When the hard drive starts to spin, I hear this sound similar to the "diskette writing" sound from old floppy drives. It lasts for 1 second or so. I can't remember if this is new of has been there the whole time, but it picked my attention lately.
As a side note, my full case fell the other day. Ran scandisk checks for all my drives with no resulting problem.
Also, when I sometimes open the Computer menu, one of my drives takes a little long to display the remaining and currently used space. This drive
Download and run the manufacturer of your hard drive diagnostic utility which is available from their web site. If the drive passes all tests then don’t worry about the sound, but if it fails then return the drive under warranty.