Hard Drive noise?

[vgcmike]

Ocassionally when i start up my pc my hard drive not very often, is making a pretty loud not stopping noise sounding somewhat like maybe a disc is lopsided. It wont stop until i turn my pc off. Is this something to worry about or can this just happen occasionally? Once i restart the pc its fine.

 

[DeFex]

I think if a disc was unbalanced it would destroy itself pretty quick (before you got a chance to reboot) are you sure it is not a fan ot dvd/cd drive that does not slow down like it should or something like that.