posted on Jan, 2 2008 @ 10:13 AM
i concur - it's either a failing hard drive or fan. fans will usually give a hum/vibration/grinding noise though. if it's a tick or knocking sound
that happens once in a while or happens repetetively every second or so then it's probably the drive. backup everything that's important to you to
cd's, dvd's, flash drives, whatever then run a scandisk. right click the hard drive in "my computer" and hit properties. go to the tools tab and
click "check now". if it's the drive then it's possible you'll see some bad sectors in the report, although not necessarily. in any case, hard
drive knocking is usually due to some read/seek problem.
if it were me i'd leave the cover off of the computer for a while. if the ticking happens you'll be able to get a better idea of where it's coming
from.
some fun trivia: the head on a hard drive never actually touches the platters when it's running. the head rides on a cushion of air so close to the
platters that not even light can fit through the gap.
anyone else old enough to remember having to manually park the heads before moving a computer? =) that gets done for you automatically now every time
you turn the computer off.
anyway, hope you get it figured out!