OK, well, without anymore detail than you are providing I would suggest that one of two things is happening.
Idea 1) Your PSU is not strong enough for your system and the read/write heads of the HDD are hitting the platters during startup.
Idea 2) Your HDD is defective and the read/write heads of the HDD are hitting the platters during startup.
This is what it sounds like to me anyways. Before I did anything too drastic, wait for MicroBell to respond, he is the Hardware Guru.
You could say I've been around.