I know this is Off Topic but maybe someone has 
had a similar experience or can offer advice from their 
expertise.
 
I am going along, and all 
of a sudden my main hard drive (C:) starts up an incessant and continuing 
chatter.  Loud enough to really notice.
There is no other 
indication anything is wrong.  CPU cycles are normal for what is open. 
(Usually have various programs with browser open with many tabs).  I have 
extra RAM and an onboard monitor does not indicate that the RAM is low.  I 
defrag automatically every night.  I have latest download/OS 
upgrades.
 
I shut down all 
applications and exit in normal manner (once I held the computer power on button 
down to shut down without going through the shut down sequence--just to try it 
that way).  Either method of shutdown makes the computer .... well .... 
shut down.  Then normal restart, and back to business.
 
These events occur every so 
many days even a week or more. It has happened three or four times, and does not 
seem to be increasing in frequency.
 
Normally, this would call 
for a new hard drive, but I have no clue as to cause and no indication that the 
drive is getting ready to fail (like increased events).
 
Any comments or 
suggestions?
 
Thanks,
Ken
 
I am backed up with full 
image of drive on external drive so I am safe 
from that standpoint.