I have a machine running Win XP Home and whenever the machine is idle for a
while the system disk goes nuts with reads and writes and never stops. I
finally determined that defrag.exe and dfrgntfs.exe are the processes
responsible. Somehow they are starting up whenever the machine is idle. It
is driving me crazy as it never completes and causes my disk drive to always
be in use. I suppose somewhere in the bowels of windows it has decided to
take idle moments to optimize data on the disk. I DON'T WANT IT TO DO THIS
WITHOUT ME ASKING IT TO!

Somebody, somewhere at Microsoft knows why/how this is happening. Please
clue in the rest of us.