SATA Maxtor Drive Clicking Suddenly and Randomly Power off

I need some help here!
I bought my pc 2 years before, including a sata maxtor drive 160 gb. My mobo is k8nf from giga-byte with nforce 4 chipset. Just a week after the phurcasing, my hdd suddenly started clicking (tac!) and getting pwoered off, while working in windows. Its temperature wouldnt go above 45 Celsius degrees. I got the pc back to the shop and they told me they didn't here that sound at all, they have just found some bad sectors on the disk, so they replaced it with a new one, same model. A year later (a year past from now), the new disk started to make the same noise again, and windows XP SP2 displaying a bsod...I contacted maxtor, they told me to check with powermax. i did it, it found some bad sectors and as it told it fixed them, but the same thing happened again. I checked my system with antivirus and antispyware tools but nothing was found. When the disk makes that sound it turns off and windows stick. After resetting the disk remains off or gets on and off continouosly, so this is nnot a software problem. What it is?

Hi

Check power cable/connector/power supply!
if the connector can be plugged / unplugged very easily, probably there is poor contact.
If the power supply is running near maximum load, power failures can occur, change the PS.

pepe