Weird sound from Computer

[patkim]

Off lately I find that some component of my PC (I suspect it to be HDD) randomly gives a ‘Ghrrrr’ sound as if something is suddenly & violently spinning for a few seconds.
This lasts only for a few seconds and then stops.

Apparently nothing seems to be wrong with PC in terms of speed, access etc
I just wonder what it could be and if it’s HDD what would it indicate.
As such I have Seagate 80 GB PATA around 2.5 years old and functioning well.

[Cool G5]

It mostly indicates Hard disk problem.
Immediately backup your data,it could fail anytime.
Get your harddisk serviced or buy a new one.

[sashijoseph]

Apart from the HDD,a cabinet fan or even the cpu fan(less chance) may be breathing/spinning it's last.Open the case and confirm.
But HDD's chances are more.