What is the ideal temperature for HDD and is there any programme or software that detects the temperature of the HDD? I think I need to install some fan into my pc as it always heats up pretty quickly. Not a good thing I suppose.

Hey, thanks for the suggestion and on another note, will installing more fan actually help to cool the hdd? I did that for my uncle's computer and though with six fan installed, of course with the proper air-flow, the hdd just seems to be hot (based on my itchy finger on the physicality of his hdd) and noisy too.
I thought by installing the fan, it should be make it cool even physically but in my uncle's case, it just doesn't seems so.