Bit of help please. I got me a new "cordless" mouse last week and a second hard drive. A few hours after installing both, I started to get an internittent high pitched "radio" type of whistle (it crackles as well), thinking that it was the cordless mouse not liking the cordless phone or wireless router on the desk, I disconnected it. I still get the high pitched whistle

Anyone got any ideas? Could it be the HDD spinning itself to death? I will try and unplug it and see if that makes a difference, but any help would be appreciated