1)   SensorsView Pro 1.2
SensorsView Pro is a program that monitors temperature of CPU, motherboard, hard disks, voltages, and fan speeds.

 2)   HDD Thermometer 1.3
HDD Thermometer is a small and feature-rich temperature monitoring tool for your hard disks. It has all the features needed to prevent overheating and possible data loss. (It can: play sound, hibernate PC, display HDD indicators and so on..)